Since the article that is hyping the belt says 8000 miles I doubt it. On a bike with no dérailleurs and a straight chainline a well adjusted and maintained chain will last a lot more than 8000 miles. Heck I have gotten that on bikes with dérailleurs. My current chain on my touring bike has a bit over 5000 mile on it and still measures out as 12.03" for 12 complete links. Sheldon Brown's site recommends replacement at 12.0625. That would seem to indicate that it might last about the same as Carbondrive brags that they have done on a belt or maybe a bit more. It isn't a particularly high quality chain and most of those miles were done fully loaded on the TransAmerica so lots of mountains and only so so maintenance.

Even Carbondrive themselves (who also say 8000 miles riding on the road) only claim 2.5 times as long as a chain. The 20,000 mile figure came from their statement that they had seen "up to 20,000 miles in the lab".