I think so, dunno in witch form, maybe would be only a change in the banner or they´ll put an advertisement at the background. And perhaps a sticky in the forums^^.
Personally, for the people who pay attention to the forums I think they'll give us a rough of a month. The main page may have a changed advertisement in 2 weeks before (my guess)
AG Should make a game with the countdown to the beta :P
Didn't they do something like that for April fools like 2 years ago?
It's possible that they'll have a timer on the banner or actually make a post in the forum, but it's also possible that lightning will strike my house, so...
Maybe we will or we won't, who knows? Honestly, I don't mind how they do it. Based on the lack of information about AG3, I guess one day I'll log in and the new version will be released.