Update: the project is currently shelved as Harold was the main implementer and he has stepped away from DMS for the time being.
I am not against continuing this project, but I am not doing this for myself so there has to be someone besides me involved. I had a chat with Jay recently and he would like to see this project continue. Depending on his level of commitment and how many new people become interested, it could be reborn yet again.
The current line of thought is we may move BACK to the no-glider radiosonde, since that will reduce electronics complexity to only needing to figure out the RFD 900 (which I have gotten a ways into), the Pixhawk / Ardupilot (also starting to tackle, need to do that for DTFB anyway) and designing an experiment to lift. Harold and Nick knew these things beforehand, but without them SOMEONE has to just knuckle down and get the expertise. And the only reason we switched to going straight for the drone was because Harold was there and could do it all.
As far as the actual balloon goes, we could fly a rock tomorrow, or as soon as we got some He.