I got the following message when I tried to access the Gaming beta:
This site is currently in private beta; it is only visible to users who committed to the Web Apps Area 51 proposal ( http://area51.stackexchange.com/proposals/57/web-applications ) at the moment. Please come back for the public beta on July 7th after 7 pm (UTC).
This is obviously the same message they were giving to people who tried to access Web Apps before now.