Normally I get access (as an MSDN member) to the RTM (i.e. finished version) of all Microsoft OS versions. This is the way that most devs. get access to the OS’s, tools, etc. For developers this is important since this is how you typically make those last minute tests on your software to make sure it’ll work with the retail version when it’s released.
With Win 8/Metro apps this is particularly hard because of the numerous restrictions about deploying Metro apps (you have to build it on 8.1 if it’s to get deployed to 8.1, you can’t build on 8.0 for 8.1 unless it’s not using anything new), putting things in the store (the public 8.0 store doesn’t work with the 8.1 OS till they turn it on).
Traditionally, the company has made new OSs available to MSDN and TechNet subscribers, as well as volume license customers. With all the changes in the new OS, particularly given the track record of MS changing the interfaces in the run up to the RTM of Win 8.0 (where they did give early access), it seems important to assure devs that their apps will work on the day Win 8.1 is actually released. It’s bewildering that they’d suddenly restrict access like this – I can only suspect they are trying to limit criticisms of 8.1 prior to it’s release. But, like other decisions the company has made in recent years, it doesn’t seem to have been well thought out.
Windows 8.1 has an October 18 retail launch.
Update: Sept 9 – Microsoft has relented under a lot of criticism; Windows 8.1 will be made available on MSDN and TechNet, and the company is also launching a Release Candidate of Visual Studio 2013 for developers. Thank you!