Sure, the nano wheel is still there. I tried to play through half the game with it and ended up using buttons instead. Why? Not because the nano wheel would be worse than the buttons, but because the nano wheel in Crysis 2 is totally broken!
Sometimes it actually gets STUCK! And I'm left only being able to walk forward, sideway and back, getting my ass handed to me.
Even more common, is that it won't revolve round properly. Veteran nano wheel users from Crysis don't move their mouse round in a little circle, we just press the middle mouse button, then move the mouse in the direction of which power we want. But in Crysis 2, I feel I have to circle it a few times, just to get it responding properly. Almost as if it needs to be 'warmed up'.
Oh, and another thing. When the suit energy runs out, nothing happens when you press the middle mouse button. It shouldn't be be like that, imo. The button should activate the menu, but the powers should blanked out in red. At least you wouldn't be looking in anther direction that you don't want to be looking in, just because you haven't realised there is no energy left in the heat of a moment.
Seriously, if it's going to remain so utterly broken, I think they should just take it out now entirely and stop pissing on the beloved memory of the much cherished nano wheel.