Vita has been dropped by Sony. They have said themselves that they aren't supporting the system anymore so it's all up to third parties, and if they stop making money off it (only in Japan) then it will stop entirely. The Wii U isn't selling well, but it is selling all over the world as opposed to Japan. Since Sony said they have stopped supporting it, there likely will not be a new rendition of the Vita because that is support for it.
The Wii U will outlive the Vita and will have far more support, so it very likely will outsell the Vita. The Vita likely only has 1 more year in it really.
Gotta figure out how to set these up lol.