Ever wonder why bicycles never jumped on the belt drive idea? If they're strong enough for a Harley or a Buell, they should work on a bicycle. Trek thought so, too, and they've introduced the Trek Soho.
Gates Technology, same company that makes the belts for Harley Davidson, makes the belt for the bike. The Soho comes with an 8 speed transmission inside the rear hub, no derailleur involved. No more greasy fingers when getting the chain back on the gears, no more cleaning a dirty, gritty chain, looks like a pretty neat technology transfer.
UPDATE: The first comment points out, belt drive bikes aren't really new, but previous bikes were single speed, you choose the sprocket you want and mount it on the bike. The Trek has an 8 speed hub which makes it (I think) the first belt drive multi speed bicycle. (Disclaimer: I'm NOT a bicycle expert!)
Link: Trek via Popular Science