Originally, we were going straight for a0.85, but some of the assets needed for that build are taking too long, so we're releasing a0.84 as an inbetween build. The changelist:
Colony in multiplayer (no NPCs or farm yet)
Monorail in multiplayer (Coop and Build only)
New objects in the Creation Editor (bed, lights, door)
Time of day is tweaked for Adventure Mode
Ramps added to towns
In multiplayer, NPC followers will no longer be auto released once they die, can be revived
Added currency to Adventure mode, meat is no longer the currency there
Added simple cut scenes for several story parts in Story mode
A0.85 is looking to be late October. It'll mainly be a pretty big Story Mode build.