I just installed Visual Studio 2012 (simple upgrade from VS2012 RC) and Windows 8 (also upgraded from Windows 7).
Windows 8 works pretty nice, but not much has changed since the Release Preview. I guess the Metro Apps (or should I call them Windows 8 WinRT Apps) are more stable and useful now, but I will probably never use them anyway. The only WinRT app that is even remotely useful is the Remote Desktop (and even that is available as a desktop app anyway), the rest makes almost no sense for a power user.
Problems with Skypekit, OpenVPN (I think I reported them earlier this year already on this blog) are still not fixed, but other than that all drivers work out of the box and everything seems fine.
The only thing I totally had to reinstall was Visual Studio 2012 because C++ Projects did not longer work, creating new C++ projects always failed and you ended up at the start of the New Project wizzard again. It seems this is broken when upgrading from Visual Studio 2012 RC to Visual Studio 2012. A uninstall and reinstall of VS and all plugins fixes this problem.
Update 2012-08-16: As it turns out the problem is connected to .NET Demon, which when enabled causes the following error when loading C++ projects (or the problem described above when creating new projects). Just disabling .NET Demon makes it work, but it is annoying, so I reported a bug here.
The error says: "Unable to cast object of type '#EMQc' to type 'Microsoft.VisualStudio.Shell.Interop.IVsSolutionBuildManager5'"
To fix it unchecking the .NET Demon options won't help, you have to unload the extension in the Visual Studio Extension Manager, then load the project (or create a C++ project) and then load the extension again (until this issue is fixed).