If MS were to release the Xbox720 2years from now it wouldn't be too difficult for them to start using this technology now and have it ready for then, of course they would undergo the same launch troubles as last year, but it worked then and could work again.
It would be least practical for sony to pick this up as they said Nintendo's way of motion sensing wasn't what consumers wanted at E3, saying that their controller used the traditional two handed style everyone is used to without the need for the external sensor bar. Then again Sony makes deals with the devil all the time so they could do this too.
The worst part about all of this I think is that the success or failure of the Fusion or it being picked up by another company(*more on this later*) depends largely on the success or unlikely failure of the Wii.
*Whose to say some other company won't decide to jump into the console market, which could also be a result of the success of the Wii, you know hey if the Wii was successful because of the motion control, what if Hewlitt-Packard decides to buy the Fusion or just it's technology and use it to make a console of thei own. Now if the PS3 is also successful at it's ridiculous price and long list of unneccessary features, what if HP decided to make a console more powerful than the PS3, with motion control and release it in 3 years, even 4 years would likely be profitable, as that is most like when the 720 would come out. They could get a leap on the competition and have what even I would have to consider as a "best of both worlds" product, of course you and I know the software is more important than the hardware, but that's not what the general public knows. If you were to ask all the press people who are praising the Wii what games they're going to buy at launch I can almost guarantee they wouldn't be able to name more than 3 games, and one would likely be a launch window game, not an actual launch game. All the press is excited about is the console itself not the software, they see they software as an extension of the hardware, I see it as the soul of the hardware, each game is a new personality.
Anyway, I'm done ranting for now.