Pro has some very nice features, I ran pro XP for just a few upgrades.Vista Business was the Professional equivalent. I actually preferred that naming convention, as it implied that the extra features may be useful to businesses. I'm not sure why typical home users want Win 7 Professional (unless they have special needs for the extra Pro features).
Well, I guess XP mode is a feature some home users would want.
Some featured you do not know you'll need them till they are gone. The stuff left out of vista that had been in XP was maddening.
Fax anyone?
http://www.microsoft.com/windows/windows-vista/compare-editions/default.aspx
I think MS is trying to leave the stink of Vista behind them by going retro with the XP names