While playing the third hub again, I encountered a critical crash and so am compelled to investigate it to ensure the stability of the existing maps. I also have discovered several minor bugs, which accumulate and so must be addressed. Of course this will delay progress towards the new hub, but I've been giving it some thought and I do think some of the existing maps (especially the Ice Pits) could use a makeover. No release date yet, but the current goal is this coming December at the latest. In the meantime, feel free to drop me any advice you have either in terms of bug-fixing, map-refining, or whatever.
After 3.1, progress will resume on 4.0 as usual.