Sony released firmware 3.68 for the PS Vita a few hours ago. Very little is known about the update for now, but as always, hackers as well as ourselves here at wololo.net advise you to stay on a low firmware. That is, if you ever expect your console to be hacked one day.
Famous PS Vita hacker TheFlowsays he will be looking into the update over the weekend. Mathieulhassumes this is just an update to change the PSN authentication key (this will block PSN access on lower firmwares).
A PSN key update could be to block PSN access to hacked PS3s running firmware 4.82, in which case we’ll soon see a new update for the PS3 as well, as hinted by CelesteBlue.
At the time of this writing , the official PS Vita update page is not mentioning the latest firmware yet, and still indicates firmware 3.67 to be the latest version. When it gets updated, expect no useful information about what the update actually does besides “improving stability”.