The app I work on dropped IE7 a year ago, and is dropping IE8 in January 2013. Therefore this is the opposite of a disaster, pretty timely actually.
They're pretty clear that 1.9 and 2.0 will have API compatibility so there is an option for those who still have to support oldIE and one for those who don't have to. Seems like the best possible arrangement.
I don't disagree with you one bit. This will vary for each company depending on industry, the average browser of the target market, and the price-point for the product.
I personally am not a huge fan of frameworks. Too often I see people solving problems by adding frameworks. Maybe I'm just a crusty guy who doesn't use a lot of tools.