Trek is mass producing two bike models with a carbon fiber, drive belt. Here is the whole story...
http://www.google.com/hostednews/ap/articl...3dr5hwD94HHL3O1

Here are the two bikes...

The single speed "District"
http://www.trekbikes.com/us/en/bikes/urban...trict/district/

The 8 speed hubbed "Soho"
http://www.trekbikes.com/us/en/bikes/urban/soho/soho/

Looks like it should work ok, not sure if I dig it just yet though, I kind of like a good ol chain. All kinds of wierd drive systems on the way, decline mag had some listed with planetary transmissions... another cannondale prototype had a lefty fork for a top tube, and a pivot in front of the bottom bracket tube, allowing a single speed suspension bike with no derailur needed due to constant dimensions in the rear tri.

Several guys down here in Durango have been running the belt drive system on their single speed MTB'S this summer and have had the belts shear in half. And it seems the jury is still out on them, set up is easy, figurin your gear ratio is odd and the cost to switch over is kinda spendy. Me I will stick to the tried and true.