The Vita depends on whether or not you own a PS3, how many games you tend to buy for the PS3, and if you're into trophy hunting.
The handheld itself is absolutely stunning, the best on the market and now that its $199, its a great value. However, the handheld relies mostly on ports and cross buy games. (Buy the PS3 version get a digital copy on Vita for free) I tend to buy ports of games that I generally wouldnt buy on a home console, like Mortal Kombat, and MLB 13. The games are just like their home console version minus a few things. For example, in MLB, there are no home run celebrations and maybe a tacked on game mode not available. In Need for Speed there are less cars on the road. Minor crap like that which you probably won't even notice
If you own PSN + the amount of games available are mind blowing. You could literally buy a vita bundle and 3 months of PSN+ and not need to buy another game during the 3 months you own the Vita. ( Though its a 16 GB card or nothing in my opinion. A 4 GB bundled card is useless.)
For me its well worth the cash, but I understand that its a handheld. There will be times where you play it for a few weeks and then dont pick it up for a few months. Before Walking Dead I hadn't played my Vita for 3 months. Next month comes Killzone, with Batman in October, and in November its YS: Memories of Celceta. Thus I've gone from 3 months of not touching the thing to probably playing it on a consistent basis from now till 2014.