The rumor of imminence has been floating around for about a month, but it was mistaken at the time. Opera mentioned something she had to do for 1.3, but wouldn't be done with for at least a week, and that somehow got translated into "OMG 1.3'll be out in a week!" Some of us, myself included, have a running joke in pestering Valkrionn for release dates, which may have confused the issue. I'm pretty sure the first time Valk himself made a statement indicating a one week timeframe was in the last day or two, as he puts the last touches on the new barbarian system.
AFAIK he hasn't given the "don't start any new games right now" warning, so my completely speculative guess is that it'll be sometime into this week. Though I'd love to see it tomorrow, as my afternoon's pretty open.