This lecture in two parts presents first a self-replicating rootkit for wireless sensors, then continues with recent research into the security of second generation Zigbee radio chips such as the CC2430/2431 and the EM250. A live demo and a vulnerability will be released as a part of this presentation.
http://www.blackhat.com/html/bh-usa-09/bh-usa-09-speakers.html#Goodspeed