According to Blizzard, they have announced in the Battle.net forums that the current beta for StarCraft II will be extended until June 7, instead of the original date which was May 31.
“We previously announced that the first phase of the StarCraft II beta test would be coming to a close in all regions on Monday, May 31. In order to prepare for the final phase of beta testing, we plan to extend the current phase in all regions until Monday, June 7. After this date, the beta test will be unavailable for several weeks while we make some hardware and software configuration changes for the final phase of the beta test and the release of the game. We plan to bring the beta test back online for a couple of weeks prior to the game’s launch to complete our testing. We’ll have more details to share about when this final phase will begin at a later date.” they said.
StarCraft II will be released on July 27 (at last).