For me, I think this marked the transition between prep and run-time. Any of my remaining prep (and there's a bunch) has moved, in my mind, into the realm of things which I'm making up for their not having been done, rather than things I'm getting out of the way. I still have a little ability to spend time doing them right, but not much.
Last year I posted about the calm before the storm, which led to some dubious comments. I see what you all meant. But even though I'm swamped with things to do, it's still that lovely part of the con, before the maelstrom has really begun; we may be busy putting plywood on the metaphorical windows tonight, but the rain hasn't started yet.