it has Wipeout on it, which meant for me it was an instant sale.
I've gotten some good play out of it so far, sure there has been bugger released since it launched, but Wipeout, Lumines and Uncharted are all excellent titles. I'll also vouch for Tales From Space and Stardust as those are great too.
Finally, Gravity Rush and Resistance come out next month and both look excellent, Gravity Rush in particular.

Don't pour water on a vita btw, I had to send mine back to Sony tech support with a phone call that went " yeah, it doesn't work anymore " "has it fallen, been dropped or gotten wet?" "... not to my knowledge?" "ok, we'll send a pick up" 3 days later, new Vita comes back, luckily, if you sign in with the same psn ID that is tied to the memory card, you don't have to install everything again and your saves are still there.