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.
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
65w ago - Following up on the previous PlayStation 3 3.70 SDK and PhyreEngine leaks, today an anonymous user under the handle ravi_h_m17 has uploaded the Sony PS3 4.00 SDK files to the Chinese file-sharing site 4Shared-China.com and the NewsGroup alt.binaries.console.ps3.