Just saw a related post at openPICUS + quadraspace... An interface that arduinos might implement one day in the future?
http://openpicus.blogspot.com/2010/04/open-sensor-network-quadraspace.html
The idea is simple (when it's genial it's always simple): create a universal language for sensors and their networks. The Sensor will join the network, it will present itself (my name is, my range is and so on) and all the data are sent to a central processing unit (a lightserver). There's a nice presentation on their website: http://www.quadraspace.org/
Looks like it's in planning/ pre-planning phase...