Check out this article i googledWin XP and IE 9, not possible? :-(Code:http://rcpmag.com/blogs/lee-pender/2010/03/ie9-hates-xp.aspx
Just read it. Well, that's the way Microsoft work. Trying to find ways to make users buy new OS from them.
Anyway, as we all know, there are much better browsers like chrome and firefox available and we hope they can maintain the lead even with IE 9. So XP users do have a choice.
I rarely use IE until its compulsory on few sites.