User blog comment:PresidentEden78/Battle Blog 10: New Trailer, More Info on Singleplayer Campaign/@comment-67.208.59.146-20110910150931/@comment-67.208.59.146-20110911231448

Near the end it says: Operation Gulltion continues 9.16.11, It's not comfirmed but it would make sence that the beta date would be that.