Should I Buy a PS Vita?

Little bit about my situation: The only PlayStation product I own is a PS2. The only "mobile gaming" I have are my Android phone and iPod Touch. The main reason I am considering buying a PS Vita is to play Assassin's Creed Liberation.

And, before you say anything, I was going to wait until the bundle comes out. With a limited edition Vita, woo!

So, back to my original question: Would owning a PS Vita sans any other PlayStation products be worth it?

Edit: I have an xbox 360 and all Assassin's Creed games for the 360.