Update: Sony has now removed PS Vita update v1.65 from PlayStation Network due to a technical fault related to adhoc play in PSP titles.
To quote: Hi, everyone. The next PS Vita System Software Update (v1.65) will be released soon and will include the following minor enhancements:
• A "Notification Alert" option will be added to Settings, so you can toggle alerts on or off
• "After 10 minutes" will be added to the time options under Power Save Settings
• An Arrow icon will now appear when PS Vita finds new activities in the LiveArea
• Caps Lock will be supported in the On Screen Keyboard
Don't forget: there are several ways to update the firmware on your PS Vita:
Select "System Update" under the "Settings" menu and download the firmware directly to your PS Vita over Wi-Fi.
Connect your PS Vita to a PS3 or a PC/Mac and update via Content Manager.
Finally, from http://wololo.net/talk/viewtopic.php?p=135560#p135560 on the PlayStation Vita v1.65 update to quote:
"I just updated to 1.65 f/w. I knew it might be a problem, but decided I wanted access to PS Store more than I wanted the homebrew stuff.
Result - no more access to homebrew, so DON'T upgrade to 1.65 if you want to keep VHBL working.
PS - The game reports that the save file is corrupted and won't allow the game to run before you allow it to create a new savegame.
I tried re-installing the game and the exploit, the open file manager still allows the exploit to be copied over, but the game still insists the save file is corrupt - so preventing VHBL from initiating.
For those curious, Sony has removed PS Vita update v1.65 from PlayStation Network due to a technical fault related to adhoc play in PSP titles.
While there is no official changelog posted yet PlayStation Vita Firmware 1.66 is expected to remedy this issue for users.
Additionally, some users are reporting that if you want to snag older free Minis that you got with your subscription, you're able to delete the non-functioning existing version and replace it with a fresh download.
As always, more details will be posted when they are available!