whaa, me too. I was changing the fore color of a label on a winform with very few controls on it. The label's color changed. Then cross hairs cursor appeared and started flashing. Then I got the hourglass. Then it all stopped and the ol "(Not Responding)" appeared on the windows title.

This is on a machine that was totally repaved prior to installing RTM bits.

ah well...

I was, however, able to close and save the app.