Taken from post on Sega.com made by SuperSonicTeam (my own profile)

So you see Perfect Dark. Pretty Graphics, better than GC, Xbox or PS2, but nothing to drool over. You see King Kong, and see the same idea.
Do you remember Xbox when it initally came out? Think Dead or Alive 3, and Halo. The graphics back then were amazing. The greatest thing about DOA3 was the "sparkle efeects", the glass spiderwebbing, the involvement with the surroundings, ex:knocking a foe off the top of DOA tower. "The faces were so realistic and beautiful!!"
Speed up 3 years. DOA2 Ultimate arrives in stores. Now palce the two in two Xbox's, line them up side by side with the same TV sets, and what do you see.
Duh! DOA3 looks like the freakish older brother you have! DOA2 looks fresher, much better looking, and more enthralling.
Halo. THe uber senstation of the Xbox lifetime. Amazing A.I., suprisingly engrossing story, and addictive gameplay.
Once again, lurch forward two years or so. Halo 2.
Which looks better? Halo 2, nix it's sometimes choppy cutscene displays, is exponentially better. And the A.I. of Halo now seems like the pile of dung Halo 2 dropped in the toilet.
Games do not merely advance with next-gen systems, but the skill of the developer creating and recreating game franchises as years go by. As you get better suited to a greater, more powerful system(s), and become less dragged by the former ones, you grow and expand, tinkering with your systems till you create a game that makes the former one on the very same system look like suck.
PS3 has potential in this case. If everything on the PS3 is as good as it looks, then it has promise for the years to come, so long as it doesn't heft a pricetag fit for kings. The Xbox 360 has settled lan first, and is lurching foward, accelerating into online, gaming and multimedia. The online terrtiory is now dominated by them, predominantly because of the powerful system Xbox Silver delivers. The longer Revolution and PS3 lounge around, the more powerful the weapons cache of the Xbox 360 becomes. Survival will be nearly impossbile for either of the others wthout online gaming and thier special 'fanboy' franchises like MGS, Halo, Sonic and Mario, respectively, to name a few.
Perfect Dark looks pretty sweet. Imagine three years from now. Now do the same with MGS on the PS3.
Even PS3 isn't blowing hot air about their graphics (remember waht they did with the PS2) and has substancial online coverage, as well as a fair sticker price, Xbox 360 will still hold firm against it even with inferior graphics. Revolution is still a wildcard mystery to us. Nintendo says their graphics won't be much better than their former system, and they, Microsoft and hopefully PS3 know that graphics won't ever make the game good. What they all need is (metal gear solid) substance (sorry about the pun) behind their games.
The fight begins in 2007. Halo vs. MGS. XB360 vs. PS3, May the best system win.