Seriously though, I signed up for notifications on your site several months ago (that's what it feels like anyway). Would love to see some progress. I had thought that custom ASICs would be too expensive given the current size of the mining economy for it to be worth it. But I guess it may be possible using an old production process. I mean, 180 nm would still beat the hell out of a GPU I suppose.
Someone has actually already made a chip capable of SHA-256 on an IBM 130nm process:
http://rijndael.ece.vt.edu/sha3/chip/sha3-asic-datasheet.pdf
If I understand the paper correctly, it does 2.95 MH/s (1.51 Gbps / 256 bit / 2) while consuming 5 mW (0.005 W) running at 50 MHz. So that's about 3 GH/s at 5 W . Though I'm not sure if scaling is that easy and simple.
Here's more info: http://rijndael.ece.vt.edu/sha3/sha3chip.html
Free samples are available . You'd need a couple hundred to get decent performance though.