I've heard of it, but I didn't find it very revolutionary. It's too similar to the PSP if you ask me. And the games that are on it are basically just ports or slightly different games from the main console.

Black Ops II: Declassified
Assassin's Creed III: Liberation
Fifa 13

Probably others, but you get the picture. What made the DS so great was that you had game series exclusively for it; Professor Layton, Brain Training, Pokemon to a degree... while on the PSP Vita, sure, you could play Black Ops II: Declassified but you could play it's bigger brother on the PS3 or Xbox instead. Same deal with Fifa.