I’m not sure why Wifi hardware vendors don’t update their firmware so that each Wifi router/bridge sold can communicate with nearby ones.
Who needs Level 3 and Worldcom if we have the ability to connect to each other over the air!
Update
This article below talks about P2P set-top boxes, i.e. the wired version of the World Wide Mesh.
Evolving Trends 
The major hassle is that every wireless vendor does things in slightly different ways, causing incompatibilities.There is no real mesh standard at the moment, although the IEEE is putting together the 802.11s standard (currently not even in the draft stage, but getting close).
I think that after an official standard has been published mesh vendors will be able to make their products much more compatible. Until then though there is no standard to follow and as thus vendors will be in chaos. Compatibility testing when there is no standard takes a lot of time.
I’m hoping for a plug’n’play approach across mesh vendors as well…so here’s to hoping the 802.11s standard is adopted (if it’s any good). :)
Can’t wait …. :)