Well, it looks like we didn't have to wait long for that iOS 5.1 update promised for today. The update is already rolling out to iPhones, iPads and compatible iPod touches. That brings with it a number of improvements and bug fixes, including the previously-announced Japanese language support for Siri, a redesigned camera app for iPad, the ability to delete individual photos from Photo Stream and, somewhat curiously, an "updated AT&T network indicator." What's more, as previously rumored, the camera shortcut is now also always visible on the lock screen for iPhone and iPod touch users.

Update: As a number of commenters have pointed out, it turns out that update to the AT&T network indicator is a change to display "4G" in the status bar, even though the device's connectivity of course remains the same speed as ever.