If you have another PSN account from a different region, like Japan or Europe, in addition to your North American PSN account, that you will be downloading content or game for, you may want to consider skipping out on the new update for the PS Vita. If you have an extra PS Vita memory card, than go ahead with the update.
The system restore loophole that allowed players to download buy cross-region downloads by backing up their data (to PCs, PS3s or extra memory cards), then wiping their Vitas and restoring them to an appropriate region, has been partially closed.
Japanator informs us that "the Vita's new v1.80 firmware also locks your memory card to your Vita's current PSN account! If you don't have a PS3 backup or extra memory card, you lose access to any data not tied to the current PSN account, including saves and DLC."
Physical copies of import games will still be okay to play, no matter the buyer's PSN Location, and are still region-free. However, Japanator reminds us this comes with some MMO-type exceptions. Most of those who will affected are those who use only one memory card between all their accounts on import purchases. To be able to take advantage of all of the new features in the update, it would be in your best interest to pick up a second memory card, if you plan on purchasing cross-region downloadable games and content.
Thanks for the tip, Akiachan!