CGRAN is useful and I'd like to see it live on in some form, at least as a directory of modules that people are developing. My gut feeling is that github is a good way forward.
I'm not sure what kind of quality assertion you want to make by including something in CGRAN (clueful developers? decent module architecture? likely to be reusable? unlikely to be abandon-/gradstudent-ware...), but having a curated directory seems better than searching for "gnuradio" and finding 527 stupid repositories of random grc experiments that only work with GR3.5.
I found the GR3.6 to 3.7 migration page last night and I suddenly find myself motivated to fork all these old modules and try update them to the new API. Anyone got any statistics on how community involvement changed after their projects moved to or from github?