Wii U: 75 M
The AAA game market will collapse in 2015, leaving the PS4 and XB1 overpowered. The Wii U will get a triple windfall from a reputation as a good support console, third party support because it has a reputation for lower production values than the competition, and first party titles undisturbed by the market collapse.
Vita: 34 M
Depends on a ton of factors, but the Vita will do rather well overall purely because it will be on the market for ten or twelve years. It will be the zombie that accumulates sales until it suddenly has a fair install base.