Last year, Sony randomly released a firmware update for the PS Vita, months after announcing that they would be ending PS Plus support for it, as well as discontinuing manufacturing of cartridges for it. Now, the year in which Sony gets ready to drop all vestiges of Vita support, they… have released another firmware update for the damn thing.
Firmware update 3.70 is out now for the PS Vita, and it does a whole lot of nothing. We can suppose that Sony will label this a stability update, and that some behind the scenes stuffed has been moved around to lock out home brew and piracy (though why Sony is bothering with a system that they no longer intend to actively support is beyond me).
If your Vita is somehow not out of charge after all these months, and you have automatic updates turned on, it should download the update and you’ll just have to install it. Otherwise, you have to manually force the update (after first finding your Vita, dusting it off, giving it a minimum charge so it can turn on, and then turning it on).