I forget myself, but I think sound as well. Don't know 100% You might be able to find out more if you go back to MKO during the E3 2004 news. That was talked about during one of the 3 days at E3 during May in the news archives here.

The difference will be slight graphical improvements and faster loading on Xbox, aside from that I doubt the actual gameplay or game content & modes will be different.

I think that the biggest difference between systems will be the controller. I've played MK:DA on all systems and I think most people will agree that there is some slight graphical and speed differences with XBOX being the best, but it is definately not enough to warrant anyone losing sleep over it. I have all three systems, but I would be O.K. owning it on any one based on graphics and loading times. I like XBOX best because I really like the S controller. From what I understand, there will not be any special inclusions from one system to the next with MK:D. By that, I mean no special characters or backrounds.
p.s.-Let's try to keep this discussion on topic and not start a system war. There has already been one discussion like this today that has been locked because people love to try to convince others that they have the best system.

I agree with Souledge316. I doubt they will be much different with the exception of graphics and loading times. And whichever controller you happen to prefer.