This is a question about how they went about with the new engine for the PS3 version because I'm extremely curious.
 
I know that this is the Mass Effect 3 engine, but how is that done? Do they have to remake all the assets (character models, weapons, etc)? Or can they port them over to the new engine and tweak them a little?
 
Thanks for any information you guys can give.

Recreating all of the assets seems like WAY too much work. I'm no expert either, though.

my guess is once they were bought by EA they had access to everything tech wise about how to work with the PS3 and since its really the unreal engine they just started from there and built it from the ground up. replacing modifying creating everything they needed they need to make their next version on the engine.

Nah, fundamentally all Mass Effect games have the same engine (Unreal engine 3) so the PS3 Mass Effect 2 should have all the same assets that the PC/360 version had. What they mean by new engine is that the PS3 ME2 would have the tweaks they did for ME3 such as improved lightning, faster load times etc.

Model assets are not obsolete when changing to a new engine all of the time.  They likely just ported existing assets to a new engine that processes everything in a nicer way.  The new engine also probably has nicer native effects to play around with to make the game more polished.  If they really did decide to replace all models with versions that are meant to be for ME3 to ME2, consider me surprised and impressed.

It's UE3, so when they say it's a new engine, it's actually just a newer version of the same engine.  All of their assets can probably just be dropped in with little to no hassle. 
 
Edit: but I'm late to the party.

Thanks for all the information guys. Even if it isn't a completely new engine (which may have taken longer, but would hopefully made ME3 an even better game) still totally stoked for both ME2 on the PS3 and for ME3.

Unreal engine 3 works on both consoles, the unreal engine for ps3 will be used for me3 for both xbox and ps3... I feel their is a huge misconception when people say new engine, just an updated unreal engine