For me, the moment I realized the Republicans were back was in the aftermath of Joe Wilson's yelling "You lie!" at the health care speech. I discounted stories from his spokesman about a spike online fundraising twice what the Dem was pulling in because that was something Democrats excelled at, not Republicans other than Ron Paul. But then it turned out to be true.
I doubt that the "worm has turned." It might be tunneling downward.
On this board, I'd say about half the Democrats got it the weekend before Brown's MA victory.
About half of the others got it just after that.
About half of those remaining might have gotten it from Nate Silver.
About half of those remaining will get it in November.
The remainder will get it, when they put down the pipe.