Why would Ubisoft be involved with a new Nintendo platform? They've jack for the current platform. If any publisher would be given first crack at it would be the one that has done the best job on the system this generation and that would actually be EA, specifically the EA Sports division. Next up would be Capcom.
Still makes no sense they would release a Wii 2 or any other new console with the Wii doing extremely well. There is no reason for Nintendo to. It most certainly won't be to please 3rd party developers just so they have another system to port their code to. The way they act now and the way they acted before they'd still just ignore the Nintendo system. Nintendo clearly seems to be able to do a nice bit with the system so they are in no hurry to introduce a new platform for their own games.
I see Nintendo releasing another add on of course. Perhaps hard drive or maybe upscaler device so games work better with HD TVs. However not a new console. That just makes no sense at all at this point in time. I won't think we'll even see a new hand held either to be honest. Another revision perhaps but the fabled DS2 just yet. There hasn't even been a proper Pokemon DS game yet. Diamond/Pearl were originally GBA games last I heard and weren't decided for the DS. Until we get a true DS Pokemon game I doubt we'll see a DS2.