People need to stop comparing the Vita to other consoles, or even the 3DS for that matter. It's a very specific platform for a very specific gamer.
If you stop looking at it as a barometer to gauge the success of Sony by, and strart looking at it as more of a portable PS3, then you can have some fun with the thing. They got it in the hands of 95% of everyone who would ever want one at this point (myself included). It's just not something that was ever going to sell 400 million units. Because of that, it's not going to have the huge expanse of games that a platform like the Wii or PS2 did/does.
But even for a hardcore gamer, there's plenty to choose from. And unless you're a very specific type of gamer (who commutes on a bus for 5 hours a day), the library of games at this point should be enough to keep you busy for the next 10-15 years. Probably the longest I've ever sat down to play my Vita was an hour at a time... if I'm going to be gaming longer than that I'll turn on my 3 or 4. shyt, FFX/FFX2 should probably keep me busy on that thing until the next world cup--no lie.
So, if you're not a Sony gamer, there's absolutely no point in getting one. But if you've been playing playstation games for 20 years and like the brand, it's pretty stupid on your part to pass on a Vita because of sales numbers, or speculating if the thing is going to be "dead" in a year, 2 years, 5 years. The thing could literally "die" tomorrow, and you'd be good until you die with the library of games out there for it.