User blog comment:Teugene/Mass Effect 3 at the E3/@comment-774818-20110601212902

Well, this isn't Blizzard Entertainment, therefore, release dates given more than the day before are not unheard of. I wouldn't be surprised if we get a specific release date. They had one up for some time on DA2.

My guess is that they're going to be mostly showing off combat changes, skill changes, etc. etc. to avoid, as stated earlier, showing off story details.