I'd pick it up but no PS3 right now, and I'd rather play it on the Vita, given the kind of game it is. Had a great time with Extend on PSP, and the demo for Diva f on the Vita was just as great.
To people who are turned off by the cute visuals: behind all that there's a quality rhythm game here. Not sure if one of the hardest, since I'm not great at them, but definitely one where it 'feels' good to play, especially if you aren't always able to do great on Extreme and what not. One of my major issues with rhythm games is how sometimes lower difficulties feel more like 'follow the visuals' rather than the music, and Diva games definitely aren't like that. Even 'Normal' and 'Hard' usually feel pretty much 'right', and you can usually get a good grasp of the rhythm of the songs just by playing it.
Plus, even if Miku's/Vocaloids voices aren't for everyone, the songs themselves sure work great for this kind of game, haha.
That said though, hope it does great and I'll be here hoping for a Vita localization, too.