New
#30
I disagree that it is just marketing. If we follow the IE9 timetable, IE10 will most likely be RTW around April 2012. This happens to coincide with Vista SP2 ending mainstream support. Hopefully, Win 8 will be well on its way to reaching RTM status.
The long XP lifespan is an anomoly for MS. They never wanted that much time to pass between OS's, but bad planning and shifting of priorities forced their hand. Worldwide, Vista has about a 20% marketshare and Win7 and XP combine for about 70-75%. In fact Win 7 just in the past months finally passed XP in terms of market share. Vista isn't even installed as an OEM anymore. Major corps. are moving from XP to Win 7, bypassing Vista completely. Vista's share in 12 months time is probably going to be closer to 10%.
Frankly, I think MS just wants to limit the number of OSs it has to support.