The next version of Windows is not going to be Windows 9. Instead, it's some kind of an update of Windows 8, that is coming next year. The Windows release codenamed "Blue" - mentioned by Win8China last week - is likely the codename of this interim release, according to Mary Jo Foley's sources.It's not clear if Blue is simply a service pack, which is a rollup of fixes and updates. Or maybe Blue is more of a feature pack, which would/could include be a rollup of fixes plus some new features.
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