It doesn't matter how long they have supported it for if they're actively dropping support now. Only SP3 is getting updates now
So? SP3 is winXP, just with a bunch of patches rolled up. it is unnecessary work to backport patches for RTM, SP1, and SP2, and it is not necessary because any legal client can easily and safely upgrade to SP3 without any compatibility issues.
and eventually that will stop. In the corporate world, companies will stop being able to downgrade to WinXP in a few years (2014 or 2015)
Eventually, yes, but its only 2010 today.
and since mixing and matching OS across the company generally doesn't work, they have to upgrade everything.
Its not as easy, but they can choose to stay with winXP.
Which brings me back to the earlier point: companies are being forced to move on from XP, whether they want to or not.
They aren't FORCED to, its just the EASIER choice to make.