Electronic News published a very nice and detailed interview with the ZigBee alliance, probably one of the most 'user friendly' articles/interviews out there revealing what ZigBee is all about and how it works. Definitely worth a read!
Read the articleElectronic News: What is Zigbee and what is the Zigbee Alliance?
Heile: We are an alliance that currently has about 105 applications for membership, and that number is increasing rapidly.
Zigbee fills a void that really wasn't addressed by any of the market spaces. Zigbee is aimed at a space that no other standards cover so we don't even see ourselves as a competitor to Bluetooth or 802.11 or any of those others.