The Multiplayer Arena Genre - What happened to it?

When I first started to play games, admittedly I did not start on the PC. But I quickly turned heads toward the PC gaming scene.
 
I remember first playing Quake and from there its sequels as well as getting into UT. I guess as time quickly passed the arena genre was ignored. It seemed that the last arena game I played that had a lot of attention was UT2k4. And that was a good amount of years ago. I find myself nearing the end of 2009 left wondering; what happened to arena games? I have not gone back to install old copies of past games to see player bases but from some research I hear there isnt a lot of people still playing them, was my research at fault? Hopefully it is. Because the last Arena game I purchased was UT3 for the PC, I also bought it for the PS3 for some reason and no one plays either at all.
 
I then look at things like Quake Live. It seemed popular back in February back when its Open Beta started. Its now August and I cant tell whether the player base dropped drastically or have the people who got into QL gone back to the original Quakes?
 
I look back at these relics and smile, but I also hate to see it drift away. What caused the genre to fall in popularity and what happened to all the players?

Free games like OpenArena, AlienArena2009 and Nexuiz (and others) are still populer (for free and open source games) so maybe you should play them? If there isnt enough people or it dosent feel right then you have lost anything really.

I think the reason Egoshooters have drifted away is because they didnt really evolve, most of what UT3 had to offer the original UT had or at least 2k4 had. While I love UT3 (and am getting a couple copies to give to my PS3 owning friends when I get my own) I know in my heart im essentially buying 2k4 with a higher quality skin.

I still play a fair bit of Counterstrike 1.6, I quite like the genre. I don't think it's so much died as evolved. Team Fortress 2 is the arena game of the now. I think that game is still very active, as is Counterstrike whenever I hop on. 
 
The players are totally still there, I think they just moved on into Halo 3 or CoD4 multiplayer, which are kind of evolutions of the genre themselves. It's just hard for an arena game so focused on solely multiplayer to have a ton of sticking power. CoD and Halo are more recently made, thus have a wider user base, and also have DLC (via XBLA, PSN, Steam) which can be a lot easier to handle for some people, as opposed downloading various created maps on a PC. Both of these games also have a strong campaign component to draw people in, so really I think it's just a matter of where the genre went. People tend to want something more than just a multiplayer experience from a game, even the most successful multiplayer focused games start losing players because a shinier multiplayer experience is offered somewhere else.  
 
There is still a place for arena based games I suppose, I just think they need to figure out a bigger draw to get, and hold players. TF2 has a very approachable artstyle, and a cool class system for people to play how they want. I think this is where the genre needs to go.

" @DanielJW: I see your point. After reading your post I just realised how much games like Halo, and TF2 are the current evolutions of the genre. I guess I just recently had a wierd bit of nostalgia haha.   Shame I dislike playing most games like those on the console. I personally did like Halos multiplayer but I personally prefer shooters on the PC. "

I still find myself playing CS 1.6 and Source from time to time. Im really surprised that game style hardly ever changed aside from a few CS mods that I find quite fun. Zombiemod, and Gun-game are a blast to play.

You brought up something I've been saying for years. I just began playing Quake Live and am better at it than I figured, though rusty. 
 
What's happened is military sims and, of course, CounterStrike (which isn't a military sim but more realistic than aliens and plasma shooters) have sort of taken over. When this started, I don't know. I think it began with the Action Quake mod for Quake II and then CounterStrike made it here to stay, or maybe our era of being at war has made people want to fight in vaguely War On (whatever) like situations instead of spaceships and empty bases. Don't know. 
 
Whether you like it or not, Halo is presently the heir apparent to the sci-fi shooter stuff that Doom, Quake, Duke, and Unreal founded.