A lot of people seem to be kicking up a fuss at all the versions Microsoft will be offering Windows in. Personally I don't really see what the fuss is about 99% of users will only see 2 or 3 of the versions and the choice is quite simple. For the non techie people you are likely to only see 1 version installed on your home PC and that is the Home Premium version.
Anyway here is a list of the possible options:
Windows 7 Starter
- Available worldwide to OEMs on new PCs
- Missing Aero UI tweaks
- Limited to 3 simultaneous applications
Windows 7 Home Basic (Vista equivalent: $200)
- Only available in emerging markets
- Missing Aero UI tweaks
Windows 7 Home Premium (Vista equivalent: $260)
- Available worldwide, to OEMs and in retail
- Includes Aero UI tweaks
- Features multi-touch capabilities
- Adds “premium” games
- Adds media capabilities (Media Center, DVD playback, DVD creation, etc.)
- Can create home network groups
Windows 7 Professional (Vista equivalent: $300)
- Available worldwide, to OEMs and in retail
- Includes all features of Premium
- Adds enhanced networking capabilities (Remote Desktop host, domain support, offline folders, etc.)
- Adds Mobility Center
- Adds Presentation Mode
Windows 7 Enterprise
- Available only in volume licenses
- Includes all features of Professional
- Adds Branch Cache
- Adds Direct Access
- Adds BitLocker
Windows 7 Ultimate (Vista equivalent: $320)
- Limited OEM and retail availability
- Includes all features of Enterprise
Considering there is currently only a $60(£40?) premium for Ultimate I am not sure why it may have limited availability? I know most people don't need it but there are plenty of tech enthusiasts with more money than sense who would happily pay the extra.