Yesterday the game worked fine for me before the servers went offline. I went and tried to log on today at noon and when i launched the game it just sat at a black screen with the little windows 7 circle loading, then errors out saying Diablo 3 not responding.

After an hour of trouble shooting i rolled back the most current realtek audio driver to the one from microsoft dated 2010. Now the game launches correctly.

I don't know if anyone else is having those issues but if you are it's worth a try to rollback your realtek audio driver.