Sure, but if you buy a vita and a PS4, it's because you're at least interested by few vita games, not only a second screen, but you get a second screen in bonus.
Joe : Indeed, you get what Wii U wont : next gen games + Sony exclusives + Vita exclusives, i think its a pretty good deal.
But if you dont have both, and want them, you should wait for a $500 PS4+Vita pack, i'm sure it'll come, they are talking about this.
Predictions for end of 2014 HW sales:
PS4: 17m XB1: 10m WiiU: 10m Vita: 10m