Ok, so the title’s a bit of an exaggeration. It’s hardly as serious as the legen- (wait for it…) -dary Blue Screen of Death on Windows.
The effect on OSX is simply a black screen with nothing but the pointer visible, and it only happens intermittently when you open up your laptop after it’s been asleep. Sometimes it goes away after time, sometimes you have to close the lid and open it again, though sometimes the machine only returns to its normal state after a reboot. Apparently the machine still responds to input, you just can’t see anything (apparently you could also ssh in and control / debug this way.)
So anyway, it happend to me the other day and I had to restart. That sucks, and isn’t what I expect from Apple. Looks like it’s a known bug. There are lots of suggested solutions but nothing definite.
Here are some relevant links,