I think this is less a sign of Sony giving up on the Vita and more another sign of the different sectors of Sony still being so disconnected from one another. Sony's general twitter posted that. If the PlayStation twitter had posted that, then it'd be real sad.
I still find that to be one of the most peculiar things about Sony. Sony has portable devices including the Vita, its eReader, phones, and tablets, but they don't see to interact with each other. Or at least their PlayStation machines never interact with their other electronics. There's no sense of a "Sony ecosystem," at least not to the same degree as what you see with Apple, Google, Amazon, or Microsoft.
Maybe this highlights that Sony is still at its heart a hardware company. When you look at the whole consumer electronics market and look at the big players, Sony is a hardware company competing against a bunch of software companies. That difference was a big part of the disparity between the PS3 and Xbox 360 when those consoles first launched. Now Sony has been forced to make good operating systems and software apparatuses really just to keep PlayStation competitive with Xbox, but all that has only been for the sake of PlayStation, not other Sony products.
I'm starting to wonder why PlayStation and Xperia are even still separate product lines. We're reaching a point where devices completely dedicated to one purpose can't really be competitive anymore, and the Vita is being hit hardest by that reality.