The Vita will probably be just a failed side project like the Virtual Boy...
...But the Wii U has Pikmin 3 so I want to get one at some point. If both products were discontinued and being sold at clearance prices I would buy the Wii U in a heartbeat but would not bother with the Vita.
And you would be a fool for discounting the Vita so easily. It
is a handheld with a niche lineup, but the Vita has more and better software than the Wii U has (and will likely ever have), not to mention better 3rd party support. Hell, Danganronpa and Tearaway
alone practically justify a purchase, not to mention the PS+ games. Don't put the Vita in the same category as the Virtual Boy, a terrible piece of hardware with almost universally terrible software (with the possible exception of Wario and that robot boxing game) and a sub-1 year lifespan.
As for the topic, the Wii U has a better future with 1st party titles than the Vita does (Sony seems to have given up on developing Vita software), but the Vita has a
FAR brighter future with 3rd party titles than the Wii U has ever had or ever will have.