ZigBee’s improved spec incompatible with v1.0

The ZigBee Alliance released a new spec that will incorporate some significant changes over the initial spec in 2004. ZigBee's market penetration is pretty small to date, so it should not have a large impact on consumers going forward. A lot of the changes in the new specification are targeted at the industrial market. If you are interested in further details about the spec, click the link below.

From the article:

One of the main differences between the 2006 and 2004 versions is a
change in the addressing scheme, said Andy Wheeler, chief technology
officer of Ember Corp., a provider of ZigBee chips and software. ZigBee
is meant to accommodate 65,000 nodes on a network, but developers found
that the larger networks were becoming unstable over time. That's
because initially ZigBee used a tree structure for addressing, which
restricted the number of addresses to well below what was theoretically
available, Wheeler said.

In the 2006 spec, a random addressing scheme is used, with built-in address conflict resolution.