Crackdown 3 is one of the big games we expect to see at Microsoft's E3 conference, and it seems even more likely now that we'll see it appear in some capacity, because over on the Xbox press site someone discovered a very Crackdown-esque screen that contains a series of dates for certain 'missions,' beginning on June 10, and ending on July 7.
Based on the stuff scattered around the edges of the site (like the mysterious BETA_INIT code), this could very well provide a date for the game's upcoming beta. We did know a beta was on its way, but we weren't quite sure when. We'll likely find out more about this site tomorrow during Microsoft's E3 press conference.