Current-gen 2K now is like the PS2 version after 2K6 (I actually preferred 2K5's graphics). The graphics (and probably gameplay, soon) won't get major upgrades anymore (and I don't feel graphics got much better after 2K9 - except for the models, but that's me).
PS3/360 = PS2. At some point we'll all have to buy a next-gen console to see some upgrades. Sad, but that's the way it is.