According to Wikipedia (http://en.wikipedia.org/wiki/Brink_(video_game)) it is based on the IdTech 4 engine. It doesn't look like it though, this game (judging from the screenshots) looks much better.
But it makes sense, because Splash Damage's last game, Quake Wars, also used the same engine. But for a multiplayer focused game, that engine has a lot of limitaions. The frame rate in Quake Wars sometimes dropped real bad, so I don't know if they can make the game as cool as its initial screenshots...

I agree it looks nothing like idtech 4, and I'd be surprised if they're still using it.

Maybe they finally optimized idtech 4 for modern GPUs and consoles?

I think you title needs some work.

wolfenstien is using id tech 4. and that game is looks great at smooth framerate. so for me there is no reason why brink cannot look at good as it does running on id tech 4

It could be GoldSrc style (GoldSrc was id Tech 1 with improvements from 2)

I'm pretty sure it is a heavily-modified version of the idTech 4 Engine. Take Splinter Cell: Conviction for example. I'm pretty sure it is still running on a heavy-modified version of Unreal Engine 2.5 (pretty sure it is called the LEAD engine), and it looks pretty good.

I'm lost are we talking about Doom 3 or something else!!!???

 http://www.splashdamage.com/forums/showpost.php?p=191939&postcount=13
 "
Its a heavily modified Quake Wars engine (idTech 4), its got a completely new renderer, new multi-core architecture (a job system for NUMA (PS3) and SMP systems), a new tools framework and lots more.

We think its the best of both worlds, get tried and tested Quake Wars tech (its often underestimated how much time it takes to get shipping tech) but with new shiny bits where required.

We hope the screen shots, show shiny new renderer is doing okay ;)
  "
 
its always bettter to cite the source then to cite a source citing it ;)

I gotta say that I really dig the style of this game.  It's got a bit of Team Fortress 2 mixed in there, but it's just sharp looking.

whatever it is, it looks pretty damn smooth.

Brink definitely uses an iteration of idTech4 (which started life as the Doom3 engine). I'm a big, big fan of this game engine, tbh, and Doom3 in particular still remains one of my all-time favourites both for gameplay and for the beautiful visuals. A contemporary of Source and Unreal3, idtech4 offered dynamic light and shadows and some advanced normal-mapping techniques over it's competitors at the time (circa 2004). In the end, idtech4 lost out to both - Unreal3 has gone on to take the dominant place amongst third-party licensees, while Source has subsequently included most of idTech4's features such as dynamic lights/shadows.
 
From what I've seen of Brink (not much, but I've seen most of the released videos to date) Splash Damage don't appear to have implemented what is possibly the engine's most celebrated assets - I can't see evidence of dynamic shadowing in any of the videos. A real shame and does make me wonder why - apart from their own experience with the game engine (numerous games developed for and published by id) - they decided to go with the same tech yet again. Splash Damage do have an inside track to id - and presumably Carmack himself - so I can only conclude they weighed up the options involved in switching out to a different game engine and decided to stick with what they know.
 
So it is idTech4, but not really as we've known it to date.

BioShock was made with a heavily modified version of Unreal Engine 2.5 so I wouldn't be surprised if this is true.

Dogstar knows what's up.  Splash Damage are about as close to iD as any other team can get (with the possible exception of Raven). And yeah Bioshock basically uses Unreal Warfare with the Unreal Engine 3 renderer, face animator and physics engine.  It's about as close as you can get to UE3 with low poly character models.  Which is why Bioshock looks like ass to my eyes.

No, he doesn't, because Splash Damage uses idtech4 great and is the first team to have succesfully used it for outdoor maps instead of Doom3's cramped environments.The dynamic lighting wasn't lost, it just doesn't work that way for large spaces, and trying to light up that sort of area with the same lighting small Doom 3 rooms did would both look wrong and bring most any PC to its knees. Quake Wars looked (and played, on PC at least) great and it seemed impossible that it was using the same engine as Doom 3 given its expansive levels, and Brink looks far better than that.

Bioshock didn't have low poly character models and still used normal mapping. The engine had more or less the same feature set as UE3 for its core aspects, just not as well developed, it didn't have low poly anything as a feature. The character design was questionable but that's not the engine's fault. It's similar to the way Valve used the Havok physics engine for Half-Life 2, yet heavily upgraded it enough to make it on par with Havok 2. Havok 2 didn't exist when they started development therefor they basically made it out of Havok 1. Havok 2 isn't exactly the Source version of the engine, though it has many of the same features. They're basically alternate evolutionary paths, one of which became official from the parent company( Epic in Bioshock's case) while the other served its purpose for the company that licenced the then available older version.

Just because developers license an engine. Doesn't mean they can't tweak the settings. Most games using a licensed engine will adjust to their liking.

Perhaps Return to Castle Wolfenstein would have been a better showcase of how one engine can look very different in different games.

Modern Warfare is a good example of a company evolving an older licenced engine on their own enough to bring it up to speed without licencing a new version. It still has the id licensing on the box somewhere, if I'm not mistaken. Then again the Havok example I gave before is good too...

who cares 
 
modern warfare 2. some people think it looks great (i think it looks ok). It is an in-house engine that was heavily modified off the quake III engine, and still has some legacy Q3 commands in it. Q3 engine is archaic. 
 
as for brink, yeah it could very well be based on idtech 4, idtech 4, like the source engine, was among the first mainstream engines to introduce normal mapping and dynamic lighting, effects that all next-gen games to this day rely on. Add some post processing overlay effects, some SSAO, some -fake- indirect lighting and light maps, and allow the engine to churn higher amounts of polys by dynamically loading meshes, and dynamic loading of textures for shaders, among other stuff and you're good to go. 

They don't put this there just for the hell of it, they're obligated to:

" No, he doesn't, because Splash Damage uses idtech4 great and is the first team to have succesfully used it for outdoor maps instead of Doom3's cramped environments.The dynamic lighting wasn't lost, it just doesn't work that way for large spaces, and trying to light up that sort of area with the same lighting small Doom 3 rooms did would both look wrong and bring most any PC to its knees. Quake Wars looked (and played, on PC at least) great and it seemed impossible that it was using the same engine as Doom 3 given its expansive levels, and Brink looks far better than that.Bioshock didn't have low poly character models and still used normal mapping. The engine had more or less the same feature set as UE3 for its core aspects, just not as well developed, it didn't have low poly anything as a feature. The character design was questionable but that's not the engine's fault. It's similar to the way Valve used the Havok physics engine for Half-Life 2, yet heavily upgraded it enough to make it on par with Havok 2. Havok 2 didn't exist when they started development therefor they basically made it out of Havok 1. Havok 2 isn't exactly the Source version of the engine, though it has many of the same features. They're basically alternate evolutionary paths, one of which became official from the parent company( Epic in Bioshock's case) while the other served its purpose for the company that licenced the then available older version. "

" They don't put this there just for the hell of it, they're obligated to:

"

"Since they licensed and integrated it into Source, Valve have been tweaking and adding to Havok to the point it's virtually a new animal. Almost every aspect of the Source engine follows on from the physics — including the sound, graphics, AI and animation. When asked whether or not they would be upgrading to Havok 2, Valve seemed to suggest they probably wouldn't, in part because H2 wouldn't be much of a step forward from what they currently have."