It hardly cannot be any surprise to anyone that Windows 8 and Windows Server 2012 has gone to RTM:

• http://windowsteamblog.com/windows/b/bloggingwindows/archive/2012/08/01/windows-8-has-reached-the-rtm-milestone.aspx
• http://blogs.technet.com/b/windowsserver/archive/2012/08/01/windows-server-2012-released-to-manufacturing.aspx

Both versions will gradually become available as of August 15th, 2012.

What does this mean for Exchange?

• Exchange 2007 is not supported on Windows Server 2012. Looking at the n-1 support policy from Microsoft I personally don’t expect Exchange 2007 will ever be supported on Windows Server 2012;
• Exchange 2010 is not supported on Windows Server 2012 yet. This will just be a matter of time, I’m not sure if this will be in the next Service Pack or that it just will be supported;
• Exchange 2013 Preview is supported on Windows Server 2012, but since this is just a preview you don’t get any support anyway

If anything develops I will publish it here.