Let's get one thing straight: I love the PlayStation Vita.
I always have. I'd probably play it quite a bit if they actually made games for it (and when I say that, I mean games I can't play on PS3 or PS4). It always needed exclusive software that it just didn't get after the first year.
Anyway, the handwriting has been on the wall for ages. Sony never even talks about the unit anymore; it was barely mentioned at last year's primary industry events, and they haven't released any numbers or sales updates in forever. No new exclusive games have been announced and any game that does come to Vita seems to be available elsewhere. The bottom line is that Vita simply isn't in the news any longer; developers, publishers, and Sony aren't talking about it at all.
It should be obvious that Vita won't survive much longer. I'd honestly be surprised if they were still producing the thing at full capacity by the end of the year. There's really nothing to be done, either; if you can't get designers to really focus on the system and tap into its substantial power, it'll never stand out. Early on, games like Uncharted: Golden Abyss and Gravity Rush proved what the Vita was capable of, as did a few later titles like Tearaway . But clearly, developers aren't interested in only focusing on a failing platform.
Whenever it goes, I'll be sorry to see it. This is by far and away the best portable true gaming device in existence.