The development of iOS 5 continues with beta version 6 available to developers via download or an over-the-air update. There has yet to be a discovery of any feature additions or UI improvements, but there are said to be numerous bug fixes (as expected).
Previous versions of the betas had some show-stopping bugs with various devices, but with September just around the corner things should be getting pretty close to stabile. If you've got access, go download your copy now.
Apple Releases iOS 5 Beta 6 To Developers [TechCrunch]