Microsoft insider Paul Thurrott, who publishes the SuperSite for Windows Web site, claims that Longhorn will ship in seven different versions when the operating system wraps. (According to Thurrott, the OS is now scheduled to release to manufacturing - meaning it's heading to duplication - in late May 2006.) Among the seven editions, said Thurrott on his site, are a Starter Edition (similar to Windows XP Starter, the edition Microsoft's pitching to developing countries), Home, Premium/Media, Professional, Small Business, Mobility/Tablet PC, and finally, something he dubbed "ber" Edition.
Imagine how many holes and patches we will get.

It's going to be very confusing.
Source : PsyOrg