I now have a Jeenode version of the room sensor deployed in my living room:
It was a little tricky to solder, but it seems to be working fine. It transmits light level, temperature, humidity, motion and a battery low indicator. It could do with a box or some sort of enclosure. I will probably add a board with a sound meter to it.
I have not yet got it connected it to the Raspberry Pi and OpenRemote. I have not decided which connection option is best: USB to a Jeelink, an RFM12Pi expansion board or a GPIO connection to a Jeenode.