I could see Nintendo coming out with a new traditional - D-pad and Analog stick/6-8 button controller type system any time now, to run concurrently with the wii. Something like the true successor to the Gamecube. It's like with the Nintendo DS. the DS is a new type of platform, the president of Nintendo has made it clear that "it's not a gameboy" and that they want to work on the gameboy3 (4 if you count GBC), but they want the DS to have a little shelf life. I could see both running concurrently, each for a different purpose, and I could definately see Nintendo doing that as well for a new, true next-gen console to run alongside the wii.

As far as XBox, I guess they might as well, they could technically say it already had a good lifespan, it pushed XBox live to the next level, and it has a massive library, it's lasted a few years. But honestly I could really care less as it seems every game on XBox is the exact same game as every other titles I've played from that genre, there's nothing new or innovative, if you just want something to game on, nothing special, then go right ahead, make a new XBox. It's maybe even necessary, because when you consider that it still uses DVD's, and compare it to the ps3's processors, the 360 is technically a generation behind the PS3.

The PS3 is a different story as it still hasn't reached its full potential. Heavenly Sword was great, but it didn't seem as revolutionary in graphics as the trailers and developer spotlights were making it out to be. It needs a game that shows what blue ray and multi-celled processing can really do. FFXIII might do that, but we have yet to see other ones to really check it out. Until that game comes out, then you can say that the ps3 lifespan is really beginning. However, because of all the things you can do on it, i could see it lasting a really long time, sony said they wanted 10 years.