Laen delivered all kinds of goodies last night, including a PCB that he'd kindly included in a trial run of the DorkbotPDX PCB-manufacturing interest group. I stuffed the board last night and got it working this morning (the only bug I've found so far is a GPIO that I didn't notice was open-drain).
It's not much to look at by Dorkbot standards, but it should do a fine job running my radiant heat system in my kitchen (and eventually, a couple more zones in my house).