You should be ready to flash. Just download from the CAI thread in the OptiS forum and you should be well on your way to cool, well supported CM9 goodness.
Awesome. I figured Tom was just working on other things. You know a programmer is busy when he doesn't update his github in a while. My guess: family. Mine's been keeping me busy the last few months as well. Also, Christmas.
I don't know if hlxanthus would be interested in a dev device, but having moved on myself, I'm using my old one to learn basic android programming on. Time to join the elite! ;)
What everyone above said, really. HydroROM is a solid choice, and being as it's stock based, required no updates because, well... everything's working. You'll never get a "Hydro ICS" for the OptiS, but HydroROM will remain an excellent choice.