Well we still have a long way to go before I'd call it a polished product that didn't have a lot of lose ends, but the whole thing is stable and the important bits are working well. The UI has also settled down so it really feels like cleanup time to us. We're launching concrete5.org to try to drum up some help from the open source development community as I type. Sadly there's nothing for me to do but bug people about getting C's in the right cases right now, so I'm posting here so my team will stop scowling at me.
concrete5.org is live! yay, tell your developer friends.