Windows Vista : 7 future versions!!

Microsoft seems to be on track to release not less than 7 Windows Vista versions : 4 dedicated to customers, and 3 dedicated to Pro.
Without giving details, the basic version will not allow the simultaneous display of more than 3 windows, whereas the most expensive version will of course be not limited as such.
This information could also explain why Microsoft could propose a Vista license for 99$, a price much lower than any previous Windows version.
People disliking to have numerous windows open simultaneously would have the possibility to pay less for this option ;)