I got it here:
Out of curiosity I had a peek at my own website's Google Analytics and looked at the browser stats for this year. Its a UK site. Stats were as follows:
IE9 - 14.51%
IE8 - 10.71%
IE7 - 1.55%
IE6 - 0.56%
On the OS side:
Windows 7 - 49.77%
Windows XP - 14.34% (which stops at IE8)
These stats don't tell the whole story, though; of the 30 or so major clients my company has, around 7 are dependent on either IE6 or IE7 in their intranet or call-centre environments. Most claim they will move away from them at some point in the future, but I can can see no evidence that it's happening quickly, due to the big corporate investment in application tools that still have a dependency on these old IE versions.
jQuery is a very useful tool because it's cross-browser. That's the whole point. V2 won't replace the current version until IE8 and below are completely obsolete and that, I'm afraid, just can't happen for many years.