I think most people are waiting for construct to mature. It got panned by a lot of people during the first testing which i thought was unfair.
It still has it's detractors. There's a bit of drama still going on over at TDC. And if I'm not mistaken, LIJI is pretty much making it his personal mission to crap on Scirra at every opportunity.
But I agree that there will likely be a spike in users once Construct is out of beta. A lot of people at TDC seem to be adopting a wait-and-see attitude. Though with .86 fixing a lot of the nastier bugs, maybe folks will start rolling in sooner.