I agree. And not only the Virtual Boy, but Nintendo released two handhelds (Game Boy Color and Game Boy Advance) with incredibly short, three-year lifespans until their successor was released.
Hardcore Nintendo fans had no problem with the Nintendo DS releasing in 2004 despite the Game Boy Advance releasing in 2001, so I don't see why the successor to the Wii U can't be released in 2015.
As I said earlier, if I was in a management position at Nintendo I'd only continue to support Wii U with the tentpole projects announced for the system (Zelda U, Mario Kart 8, Smash Bros. U, and the other projects Nintendo has in development).
Nothing major would get greenlit at this point.
Due to Nintendo's excessive inventory of manufactured Wii U consoles, I would halt production for the time being. In territories where Wii U has flatlined (the UK / Australia for example) I would stop paying retailers to keep Wii U on the shelf and retreat from physical retail at those markets. At the end of the day, those markets are just losing money.
In markets with at least a glimmer of promise (France, USA, Japan), I would release the tentpole projects to those territories.
Essentially, the goal is to squeeze whatever life Wii U has out of it before discarding it and moving on.
To that end, I would stay far away from an official Dreamcast-esque discontinuation. Like Nintendo did with the Virtual Boy back in 1996, I would continue to pledge support for the system but wind down 1st-party support through early 2015 before silently discontinuing it.
Who knows? In 2015 Nintendo could even invest in some small, indie-style first party projects like Pushmo on the Wii U to sustain the illusion that Wii U is still being supported.
So all of that expansion Nintendo EAD has undergone? I would invest their energies towards what's coming next, not to try and prop up a dead console.
What you say does make a certain amount of sense and I can see them doing something like that.
However there are some unknowns that could affect the whole thing.
1) If they want to bring their console features set up to par with the competition they would need more work on their network infrastructure and OS feature set. That takes time.
2) If we are talking something along the PS4/XBO level of power does a PPC based system cut it? If not that's a massive change to not only their production but also their toolchains etc.
3) If they are looking for something "real different" like their own Nintendo holodeck, that takes R&D money and time too.
I'm not sure 3 years is enough for all this to come together.