YES, JQuery 2.0 has been released, which does not support IE8 and previous.
BUT, JQuery will continue to simultaneously support a 1.x series — current 1.9 and plans for a future 1.10 even — which are API-compatible with JQuery 2.0 and which do support IE 6/7/8.
JQuery is choosing to offer two versions, both of which will function identically (modulo bugs), one of which supports IE 6/7/8, and one of which does not.
That is, if you have a site or app where you do not need or want to support IE 6/7/8, you can use JQuery 2.0 and future 2.x. If, on the other hand, you still want or need to support IE 8 or below, you can and should keep using JQuery 1.9 and future 1.x.
I have seen a lot of confusion on this. It is not true that “JQuery no longer supports IE8.” That is not a good rationale for dropping support for IE8 in your app, because it’s too hard since even JQuery doesn’t support it anymore. Not true.
You could deliver 2.0 to some browsers and 1.9 to others, although I’m not sure why it would be worth the trouble at this point. I’ll probably just keep using the latest JQuery 1.x, so long as I am writing apps that have to support IE8 or 7.
Although honesty, with the stated commitment from JQuery to keep supporting 1.9 with IE 6/7/8, I don’t entirely understand what the benefit is for their self-imposed fork either. Perhaps in the future (or even already?), if you do deliver 2.0 to capable browsers, those browsers will get better performance from jquery? Not really sure.
But don’t worry, the jQuery team still supports the 1.x branch which does run on IE 6/7/8. You can (and should) continue to use jQuery 1.9 (and the upcoming 1.10) on web sites that need to accommodate older browsers….
…The jQuery team will continue to support both the jQuery 1.x and 2.x lines simultaneously for as long as those older versions of IE are still a factor. The currently released version of jQuery 1.x, which is 1.9.1, has the same API as jQuery 2.0. We are planning a 1.10 update to the 1.x line in a few months that will address any minor differences in the two versions. At that point we will still keep the two lines in sync: 1.10 and 2.0, 1.11 and 2.1, etc.
Bibliographic Wilderness 
“You could deliver 2.0 to some browsers and 1.9 to others, although I’m not sure why it would be worth the trouble at this point.”
To provide a better experience to your users. 2.0 removes a lot of code that has the sole purpose of supporting legacy IE. Remove that code, and jQuery is a smaller, faster library, making your website smaller and faster. A simple conditional comment to show 2.0 to most browsers and 1.9 to legacy IE provides a happy solution for everyone.
jquery 1.9.1 not supported in IE8 in my website.