The thing is Enterprises or business do not like new software or new OS do to it cost them money . So Microsoft is in it for hard fight.
And cost money to get new software ,new OS and train people and they new windows XP with SP 3 it all just works . Well they do not know that about windows 7 or windows 8 to all the reviews come out.
One of the things about windows vista it did not support old software.And the public and them hated MS for that.
But what can Enterprise and Business users do? Microsoft pretty much monopolizes that market, with IBM doing the beefier backend stuff for the biggest Businesses.
They'll have no choice to upgrade. No other company can provide them with what they need.