I think you missed the announcement where Microsoft is going to do a silent update of IE10 to consumer PC's. IE9 usage will drop to the low single digits within a year and IE10 will take its place as the leading IE browser.
How's this going to work for corporate installs? As much as I love the idea of big companies being forced forward, I have the nagging feeling that Microsoft will include a get-out-of-jail-free card for them.
(Speaking as a medium-sized corporation user stuck on Snow Leopard. :] )
The "force" upgrade everyone is talking about is an optional thing. You will be able to go into the settings and turn that off (specifically for corporate use).
IE9 doesn't run on Windows XP. IE10 won't run on Windows Vista. So it's safe to say that even with silent updates (which still won't automatically run on corporate machines with corporate IT policies that control the updates), IE8 and IE9 usage won't rapidly drop into low single digits.
IE8 will probably be more persistent than IE9. I think a lot of corporations are still on XP. Mine is, for example. When companies finally make the jump to Win7, I think they'll move pretty quickly to IE10, so as not to be too far behind. After all, we should expect IE11 next year.
As a note, at my company last year the xp images JUST got IE7. And last week, as the first group of people, our group got upgraded to Win 7+IE8. Major corporations are slooooow at updates.
I'm just happy its happening at all, I know people at banks that have IE6 still.
(Speaking as a medium-sized corporation user stuck on Snow Leopard. :] )