I've just caught up on this thread. You've done some great work here, and like everyone else, I'm very jealous of your 3d printer access. I was originally thinking of some legs like yours, but I don't have the inspiration or time to make something like that without a 3d printer, so I've just gone for flat perspex cutouts.
It's great reading through and finding that you have come up against many of the same issues that I have been working on. I was originally considering hacking servos with PIC controllers and I2C/SPI, and I may still do that, but I'm way early on in the process compared to you, so I'll be getting it all working with standard servos first.
I was reading your posts on the IK speed. I've just finished optimising my IK code. I'm running an 80MHz PIC32, so performance is pretty critical, but I managed to get the IK code optimised to run at 190Hz, running 20 joints, including walk cycle. Not bad, huh? I was pretty happy when I got it to that level. There's also some special methods in there so that it resolves almost perfectly in each iteration, even for large jumps in foot position. This means I only need one iteration per servo-cycle, so I have 70% of the CPU still spare.
I am also planning to do video, but that's a ways off. I don't know if the PIC32 will be fast enough to do the face detection thing. Time will tell.
Keep up the great work. I'll be watching!