The first 2 beta versions of iOS 5 expired at the beginning of August, but in iOS 5 beta 3 Apple extended the validity period. If you have iOS 5 beta 3 installed now, you can use this version of iOS until August 18, when the terminal will inform you that you need to update to a new version of the operating system. We will probably have 2 more beta versions of iOS until the official release and in the meantime Apple will extend the validity period until September of this year.
The validity period of a beta version of iOS does not indicate the possible release date of the final version, so do not be guided by these dates to guess the release date of iOS 5.
