I received Quake Wars with my 8800GT. Haven't played it much, but what I've played is pretty much meh. UT3, however, is fast, fun, and addictive. I live for the announcer saying "HEAD SHOT!! I've played some warfare in UT3, and it's like onslaught from 2k4; control the nodes leading to the opposing team's node, then attack it until it blows. I'm more of a fan of mindless deathmatch, but warfare and vehicle CTF are very fun.
As far as I know, no headset support. Haven't tried a gamepad, but it's not Games For Windows certified, so probably not.