I hold on to PC over any console for a few reasons still:
1. Choice, the massive amount of software available to a PC. No console yet comes close, and seeing as the PC is also most compatible with a huge selection of games, I chose the PC. It has everything, I don't need to have a PS3 AND a laptop because the PS3 can't do all the tasks I need it to. It's so much more comfortable to have everything in one place, and until I can do that on another platform I'm extremely unlikely to cross over (that naturally depends on what happens to the various platforms in the future).
2. Upgradable hardware and software. It's relatively easy to upgrade any PC, with even just a limited amount of knowledge, like what I have. I'm not skilled, I most likely couldn't answer any of the questions a somewhat learned person in the art of PC would ask me, but anyone can learn to upgrade basically any part of a PC in the matter of minutes. Meanwhile, other platforms don't allow this. Being "bound" to one hardware setting may be good for compatibility, but that also means you HAVE to wait for the new machine in the series to come along, and then pay the full price, rather than just toss in a small sum in upgrades for your PC and be able to run whatever piece of software you needed the upgrade for.
3. Full choice between keyboard/mouse, Joystick or most other controllers. Most games now will allow you to chose between using the keyboard/mouse setting or another alternative control unit like for example the xbox controller, which I prefer for many games over the keyboard. You can have all these alternatives on hand and get playing at any time... Meanwhile, your unable to use a keyboard/joystick for games on the PS3 and xbox, as far as I'm aware (and btw, if I was to get one of those consoles, it would be the PS3), though something may have happened that I have missed. I feel I need the choice to enjoy my games to the fullest.
That being said, I would love if the console could offer me those 3 things. If they could, I'd be there instantly. Sitting in the couch and doing stuff on a big screen would be great, but there's just too many things I would miss by crossing over right now. And I know the whole "needing a separate laptop" isn't a big deal for most, but it is to me. I have an almost obsessive need to have everything in one place, and in a very particular way of order.
Steam too, I LOVE having all my games at one place, I've almost completely stopped going to the store to buy a game, I basically do it all online... It means no covers, no discs, all my games in one very neat and very tidy place.