You know you can hook up your PC to the tv and use a wired/wireless 360 controller. Just sayin.
Yeah, that is a good point. My gaming rig is in need of upgrades (or more likely replacement) and sitting with KB/M at the desk is one of the reasons I like FPS on PC when I do play that way. If I am going to be using a controller I would rather be playing against people who are using controllers as well. The response just isn't the same and there is nothing worse than feeling at a disadvantage right out of the gate. It is kind of the reasoning why noone supports the KB/M on PS3 when it is doable.
I guess the friends list I have established on 360 is a bigger reason than the couch/TV anyway when I think about it. Having a solid group of people with like schedules already set to draw on, with reliable gaming skills besides, is a big factor. Many of them are form L4D/L4D2 as well so they are already used to FPS teamwork of some sort, which is probably going to be something very helpful in Brink. I would basically have to start fresh on PC, and I know very few people who game on anything but their consoles anymore since I have been away from PC gaming for quite a while.