I don't think unlock hacks are possible for this game.
MW2 is a whore with no address. Do what you like.
BC2 is more like the daughter of a cop. Can't do much.
All information is stored on EA's servers so rank/unlock hack isn't possible as far as I know.. You will be able to get aim/wall/ESP hacks like most games and maybe texture/sound hacks once people figure out how to edit the contents of the .fbrb data files.
I don't know the potential of injecting .dlls into game .exes but I doubt you can make an unlock hack by doing so(?).