Phineas, why would MS continue support? There's no money in keeping WinXP alive, only costs, and a whole pile to be made selling licences for new Win7 capable software.
The corporates will suck it up because they can't afford to risk being caught out running an unsupported OS. What's the lead in time for a corporate migration? 18 months? Two years?
Not to mention third party software vendors cutting off support on XP. Risking running an unsupported OS and critical business software doesn't sound terribly smart to me.
And that just leaves the home user. Definitely no money to be made there continuing support.