If you like home consoles and want something that deep but readily available when you don't have access to your PS3, the Vita is your best bet.
For a few months I didn't have a TV, so I got a Vita and it fulfilled my home gaming needs very well, with the plus that I can use it anywhere. Playing Uncharted or Gravity Rush when I am for instance waiting in the mall for my wife for an hour feels great, I forget where I am and can have a deep, home console-like experience. So if that's what you're looking for go for it
I think it's worth it even if you only consider the games that are already out or announced. Especially since you need something to kill time badly.
But definitely wait for one of the holiday bundles (Vita+game+memory card for the same price). You'll save a LOT of money, it's almost too good to be true.