Being the fanboy of this series as I am, I just had to see what this would look like on the PS3. To be completely honest, my feelings are a bit mixed. When one time I'm thinking,"Wow, that's pretty.", the next time I'm thinking,"Wait, I've seen this before."
What I mean by that is that it's a slight improvement over the 360 version, but not THAT much. The most noticeable things that I saw the minute I started playing it was the slightly sharper graphics, and the distance scaling. Although I ran into quite a few glitches that were already cleaned up in the 360 version, which are negligible since they'll probably be fixed with an online update(That is, if sony actually does it).
One big bonus for PS3 owners is that is comes with Knights of the Nine expansion, which is still for sale on the Xbox Live Marketplace. My thoughts, if you have a PS3 and do not own Oblivion on anything else, GET IT NOW! If you already have it for the PC or 360, don't bother, there's not much of a difference.