Following their previous PS Vita System Software update, today Sony released a PlayStation Vita Firmware 3.71 update which scene developer TheFloW has confirmed fixes all of the bugs used in the Trinity Exploit chain blocking those who update from using it. 
Needless to say, it's advisable NOT to update as most PlayStation Vita sceners got a PS Vita or PlayStation TV to do fun stuff like jailbreaking, running exploits and homebrew on the handheld console while this revision patches the holes preventing such things as detailed in TheFloW's Security Blog.
Download: PS Vita Firmware 3.71 Update (US) / PS Vita Firmware 3.71 Update (EU) / PS Vita Firmware 3.71 Update (JP)
As always, we'll update this article when Sony posts an official changelog for the PS Vita 3.71 Firmware update.
3.71 firmware_compare with 3.70
How To Play PSP Games On 3.71 FW Vita Without HENkaku/Trinity!

Download: PS Vita Firmware 3.71 Update (US) / PS Vita Firmware 3.71 Update (EU) / PS Vita Firmware 3.71 Update (JP)
As always, we'll update this article when Sony posts an official changelog for the PS Vita 3.71 Firmware update.
3.71 firmware_compare with 3.70
How To Play PSP Games On 3.71 FW Vita Without HENkaku/Trinity!