Apple has released iOS 5 Beta 5 (build 9A5288d) to developers, alongside with Xcode 4.2 Developer Preview 5, iTunes 10.5 Beta 5 and Apple TV Software beta 4.
Like iOS 5 Beta 4, Beta 5 is available as an over the air update at only 128MB. However, the new beta firmware is still downloadable from Apple’s Dev Center at 787 MB.
According to the Read Me file, one of the strange things about this update is that users must first erase all content and settings by choosing Settings > General > Reset > Erase All Content and Settings. However, according to MacRumors, some users have been able to upgrade fine without going through that process. BGR has posted the full release notes, which details some fixes and changes.
As always with any beta, it is recommended that you backup your device either via iTunes or iCloud prior to installing the new software.
MWD predicts that the public version of iOS 5 will most likely be released sometime early September.