The VPN server fix was a big one for me, as I now have secure remote access. Just yesterday I remotely added a new PIN code to my front door for my nephew who was coming over when no one was home, and it worked perfectly. That is the first truly useful thing I've been able to do in terms of home automation.
Power monitoring for my smart switch is proving to be fun to play with (now that I'm getting the SDK figured out), but there is a long way to go with my thermostat, general home automation (events and the like), etc.
What I'd really like to have is some kind of "How to add sensor support" guide: I have a light switch which shows as an "unsupported device" that I'd really like to use. If all the backers had some guidelines on how to help add sensor support, we could really ramp up the collection of working devices