Included in the update is a cool feature called screenshot mode, allowing you to take cool pictures of your characters in front of lots of backdrops, including the racial capital cities. The screenshot mode will even remove all of the interface elements from the phone, giving you a clean shot.
This update could be laying the groundwork for the newly revealed mobile guild chat service available through the armory app, potentially unlocked in the near future for subscribers to Blizzard's Remote Auction House service. Hopefully, more light will be shed on this functionality in the near future. Until then, get updating, because these new features are pretty neat. Previously, I would have had to bookmark the armory's RSS feed for my characters and open them in Safari on the iPhone, but with the new activity feeds built right into the armory app, things have gotten a lot less clunky.