If you mean modes and gameplay, the PC version will be identical to the console versions. Previous games suggest that details such as lighting and textures may be slightly different in the PC version, there was an issue with small court logos in NBA 2K11 and I believe the console versions offered custom soundtrack options that the PC version did not. Aside from that, it was the same game.
Obviously the PC version will not support things like PlayStation Move or Wii controls, which are exclusive to their respective consoles.
Jersey swaps are nothing new. If you have the knowledge and skill with Photoshop/GIMP, it certainly can be done. I myself can't do it but plenty of portrait patchers have done it in the past.
The manipulation of the portrait photographs would be the same, working with NBA 2K12's files would require different tools though. Hopefully the ones we have at our disposal will work or can be updated not long after the game comes out.