That's funny, because if you look at the specs, the video formats of BD and HDDVD are essentially identical lol. Also, the Xbox actually tends to have a farther draw distance than the PS3, and the texture resolutions tend to be higher. On paper the PS3 is actually more powerful than the Xbox, but it's far more difficult to harness the power of the PS3 than it is on the Xbox due to the more intricate processing architecture. The PS3 has several processors that do more specific things, whereas the Xbox has a general-purpose hyperthreading triple core 3.2GHz processor (allowing for the processing of 6 threads simultaneously, effectively making it comparable to a 6 core processor). When talking graphics processing alone, the Xbox's Xenos GPU is superior both on paper and in practice due to its higher fillrate, higher pixel processing power, higher vertex processing power, and better memory architecture. Also considering that antialiasing is free on the Xbox, the PS3's RSX simply doesn't compare (though the Cell processor can be used to assist with the graphics, most developers haven't harnessed it well enough).
So to sum everything up, basically the only games that are going to look better on the PS3 are the super-huge AAA titles like MGS4 and Killzone 2, which are both proprietary only to the PS3 so they don't require porting of any sorts, and would be insulting to the console if they didn't look as great as they possibly could.
And that concludes our broadcast day.
PS: Sorry for the thread jack lol.