I got a couple in mind:
Freezing (i'll be optimistic: i hope it's not a problem)
OP perk combination
Controller specific problems (once again, i hope it's not a problem)
Well, if there are no problems besides in-game object balancing issues, then that would be spectacular.
power brought back to wiimote OP this time around, will be partialy fixed later.
probly some map based issue. probly wont be the same as MW3's map based issues.
will probly have framerate issues, hopefully not freezing, but that depends on competant the 3arc team making the version is, should come out better than wiiU version of BO2 though (fixed compiler issues and rushed wiimote controls, several things to big to fix in a simple patch, also wouldnt be surprised if AtreyU +2-4 guys worked on BO2 wiiU version. )