Whatever plans you had for this summer, cancel them.  Blizzard has officially given Diablo III a release date.

The game will arrive on store shelves on May 15 of this year.

Blizzard is still running its promotion of if you pay for a WoW Annual Pass, you will get a free copy of Diablo III.  However, the promotion will expire on May 1st.

If you can't wait, you can go ahead and pre-purchase the title and you will be able to download it 12:01 am on the release day.