Jeff Alexander has posted the complete SKU Lineup for Windows 7.As it has been known that Windows 7 would be released in six flavours

• Starter
• Home Basic
• Home Premium
• Professional
• Enterprise
• Ultimate

This slide gives you a quick overview of all the versions of Windows 7.

The primary 2 editions are  Windows 7 Home Premium and Windows 7 Professional.  Windows 7 Professional replaces the Windows Vista Business SKU and is the targeted version at small and lower mid-market businesses. Like it predecessor Windows 7 Home Basic will offer a basic version of the Windows interface.  The major change is this is the edition that will be targeted at emerging markets.  Windows 7 Starter is an even more stripped down edition than Home Basic and will be offered to OEM partners.  Windows 7 Starter only allows 3 applications to run at once.  The other 2 editions rounding out the 6 are Ultimate and Enterprise.  Ultimate is the upper version that has all features enabled.  And the Enterprise edition is only available to customers that have an SA agreement with us.

Here is the summary of major features in different versions of Windows 7