The second beta of iOS 7 has just made it to the Apple Dev Center, hopefully bringing some new features and bug fixes to the iPhones of developers worldwide. This release goes out two weeks to the day after iOS 7 first became available to developers. The beta is available by going to Settings > General > Software Update on devices running the current iOS 7 beta.
According to developers who have reached out to TUAW with information about the new beta, it contains the usual "bug fixes and improvements." A document outlining the changes is available to developers at http://developer.apple.com/ios7/release-notes/, although several devs reported that the page is currently offline.