It's a bit inconsistent, but I find i kinda like the fact that the CPU will punish you for not being in the right position. If you sag off on the weakside, then try to recover, you cant just run out and suddenly be stuck on the offensive player...if you don't recover with discipline you'll get blown by. Love that. I think the positional defense thing is cool...but I can see the new cheese are being the shake/bake and pull up game.
Cheese isn't just dunking. Cheese is exploiting a systems weakness repeatedly at the expense of realism. Casual players will figure out the new easiest way to score, and they will pound it down your sim throat. The midrange game and lack of consistent contact on the perimeter will definitely be cheese, and there will be lots of whine to go with it, lol.
Don't want cheese? Don't play cheesers. It won't be Live's fault...they've given folks a nifty offensive/defensive balance to work with if you choose, and it feels great.