It's a pair of half wave voltage doublers, one positive one negative. R11 and R12 are stop-gap measures that I put in place to make sure that the caps that I'm using that are too low voltage don't see more than their rating -yes I'll have to change them really, but I'm certainly now considering investing in another transformer and a 6080 and making a poor mans Crack.
I had forgotten until you reminded me that the SOHA II uses an active current mirror load, I had been browsing TubeCAD and decided that the Common Cathode amplifier was a nice front-end if I wanted to keep two complete dual triodes in use in my amp, because as has been noted in this thread, there's no real point in paralleling tubes to drive a high impedance load as you just get increased Miller Capacitance. On my first proof of concept however, I had just used a plate resistor (I have a trimpot on the cathode even though I only put a resistor in the schematic), but to get the I and V that I wanted I was oblidged to use a load that was far too low for an ECC82/12AU7, so I looked for another alternative and remebered how much mirrors like this increases that impedance (this must have remained in my subconscious from when I last looked at the SOHA design pages :D. After applying these changes the amp sounds much more full.
Personally I woudn't be inclined to use only a tail CCS and would instead look to what I see as one of the best CCSs in existence, the one that is used in the torpedo with an LED biased shunt on the cathode, I think that the PSRR that an anode CCS affords is really not something to be missed if you're going for a CCS... I'm currently trying to get a more tubey sound, which is why mine is biased with a resistor.