A new mandatory firmware for the PlayStation Vita is now available.  Here’s the changelog:

You can now easily upload and download your saved data using online storage. Select the PlayStation Plus icon on the LiveArea screen for each application.
Some items have been added to the menu that appears when you press and hold the PS button.
[Devices] has been newly added under [Settings], and [Bluetooth Settings] has been moved under [Devices]
In addition, the usability of many features has been improved.

To update just use the Network Update option from your Vita’s menu or manually download the firmware by going to this link link.