I thought I had seen when I first started with Mango there was some discussion of implementing X-10 for Home (or other) Automation. Has this died or is there still a possibility? X-10 Power Line Carrier is a great way to avoid geeting involved with mains voltage when desiring to control various AC devices. It's pretty much plug and play and widely available from many suppliers.
This hasn't died, no, but nor has it come up much. I would suggest implementing as a module for M2M2.