So, I just today had my new keyboard delivered, and I'm really excited t o be able to play SC2 again...  but I'm also terrified.  It's been nearly a month since I last played, and I'm worried I'll just get stomped all day long if I jump in. 
 
I'm thinking of watching some Day 9 dailies I've been skipping, maybe warm up with a custom game.  Or should I just go cold turkey and start laddering again?

yeah! day[9] is always an inspiration for me to play.  I watch one of his more educational dailies and then just focus on core aspects of play in ladder matches and it's super fun.

I would also recommend the warm-up route. I hadn't played a game of MP SC2 in like the two weeks leading up to the last GB tourney (was intent on beating campaign on brutal) and while I did a couple vs AI games just to refresh myself on my build orders and such, I was still SUPER rusty when it came time for me to play my games.

I would just start laddering again, but i'm not really concerned about my win/loss since I want to be playing people at my skill level anyways thats just me.

Just do some customs games. They don;t count at all so even  if you get stomped it don't matter. 

Hmmmm

Just play. If you go on the ladders and you get your ass kicked because your making mistakes, then maybe go back and practice a little. If its just because everyone has gotten better or doing new and different things, then just keep going

I had the same experience and I just played a custom game against the AI a few times. It was horrifying (and I'm down in Silver, so my skills didn't even have that far to drop!) It helped though.