Well, I guess this is my second ever PCB so I really shouldn't have been so optimistic about it being perfect on the first iteration. The board itself baked beautifully (though in the future I'll be using a stencil).
The problem is that I seem to have neglected to connect the MOSI line, which means no data out of the programmer. It asks for the header on the chip and gets no response, so it refuses to program. A problem to say the least.