I heard a few weeks ago that 35 eps were ordered. It'd make sense, considering they're set to air midseason early next year. I'd like to see Fox take first stabs, just to show big network interest, and maybe it can get some good publicity airing on Sunday's animated comedy lineup now that Futurama is no more.
Everyone was back filming in Australia. Primary shooting wrapped a week or two ago. It is supposed to be a 4 hour mini-series. No "official" announcement has been made yet, so we don't know the title, schedule, network, etc. (a bit like B5:TMoS).
I read somewhere it's 22 episodes for now, but I'm not worried because the fan base is so strong that it'll get renewed after that. And with no dumbass schedule shifting on the Cartoon Network, things look good.