I love my consoles, but I hate controllers. I am much more comfortable with a mouse and keyboard, and much better at FPS for the PC.
Console controllers don't respond as quick or as accurate for me. I know that some folks are opposite. I can tell because of how quickly I get fragged in Gears of War or Resistance:Fall of Man. However, in a multiplayer game of F.E.A.R. on the PC, its a totally different story.
The keyboard can be hooked up to consile with USB, but I wonder if the mouse will ever be supported. I admit, I like to sit comfortably on my sofa and play. With a mouse and keyboard, it just wouldn't be the same. But I would also like to be more competitive in console online games, and the only way I can see that happening is if I get my preferred controls.