Reason I say wait till holidays to judge is because this holiday we will see the launch performance (most significant portion) of some of the most important games to come on the Vita, as far as the West is concerned, that is:
Little Big Planet Vita, Assassin's Creed 3: Liberation, Playstation All-Stars Battle Royale, and Call of Duty:Black Ops Declassified.
These, apart from an eventual GTA, are some of the most crucial titles to come to the system. If they fail, it would pretty much be game over. So for now, let's wait and see.
In all honesty, do any of those games seem like system sellers? They may sell decent themselves, but they won't drag Vita out of the hardware grave it's in. This is while all the while 3DS and smartphone gaming is gaining momentum. The only one I could see moving some systems is Playsation All-Stars Battle, because that games makes sense on a portable. The rest of those games I belive most gamers will stick with their console counterparts.