Ive had debates with friends of mine over who will be on top again, and it all depends on a few factors...
1. PS3's use of the Blu-Ray Disks.
2. the boomerang controller they made which can fit in the palm of my hand.
3. Nintdendo's third party support and controller use.
If the Blu-Ray disks become popular, then PS3 will most likely survive. Just because they are using it for the PS3 doesn't automatically mean that Blu-Ray is better than traditional disks, or the kind used on the Cube. Besids, there are holographic disks in development, something that Nintendo and Microsoft have their eyes on, and they are stronger than Blu-Rays.
Now that damn controller needs to be revamped,and I believe Sony is doing so, sort of. I don't know what they plan to do, but it looks horrible and doesn't look like it will play well.
Now to the main problem. With the revolution controller out now, 3rd party support has been stronger than recent years. A lot of developers are going to Nintendo, praising them and developing games for them. Specific teams. The problem it poses is that none of the mainstream developers, EA for example, would care about how this is implemented, and make a shoddy attempt like they do every year with the 50 sport games they make for the cube because they have to. Hideo Kojamas team from Metal Gear Ac!d is making a game for the revolution, as are various teams from Capon, Sega, Atari, Namco, and Square Enix. So there is hope, as the support is coming back.
So for me, I say it has a shot at being real big, but it is going to be a fight to get up there.