A new "Copy" feature lets you copy the currently displayed authentication code into your device's clipboard. You can then paste it into other text entry fields, such as when accessing Battle.net Account Management on Safari.
Miscellaneous UI improvements.
Obviously that second note isn't all that exciting, but I think the first one is worth mentioning. This is a feature users of the mobile authenticator have wanted for awhile, not just for Safari but also for Blizzard's other upcoming app. To be more specific, the Auction House app that Blizzard has recently announced (which I hope and pray is as good as Fallen Earth's mobile app). You'll need to log in to use it, so you'll most certainly need to use the authenticator that's on the exact same phone. Since the iPhone doesn't let you use two applications at the same time, this copy feature is going to be a welcome addition. Sure, you could just remember what the generated code is, but this is 2010. Who remembers things anymore? I have computers for that.