Microsoft said on Monday in the US that the server version of Windows 7 would not be a major release and will bear the name Windows Server 2008 R2. In the past, Microsoft has used R2 monikers to signify a product with a few new features, as opposed to major changes to a product.
Microsoft declined to discuss what will be in Windows Server 2008 R2, but a spokesman confirmed that it is the server version of Windows 7. The release was due sometime in 2010, Microsoft said.
On its server roadmap page, Microsoft describes its minor, or update releases this way:
News: ZDNet Australia
Update releases integrate the previous major release with the latest service pack, selected feature packs, and new functionality. Because an update release is based on the previous major release, customers can incorporate it into their environment without any additional testing beyond what would be required for a typical service pack. Any additional functionality provided by an update would be optional and thus not affect application compatibility or require customers to recertify or retest applications.