Today we have released a hotfix to the Skype 5.9 for Windows.
The newly released build resolves an issue which made Skype to use excess amount of system resources on the Windows 8 Release Preview, build 8400.
We would recommend for everyone to upgrade to the latest version.
Full release notes for the Skype 18.104.22.168 are:
|Generic||Skype used excess amount of system resources on Windows 8 Release Preview|