As for the title question - I've seen plenty of furniture, big screen TV and computer rental/leasing companies. The above post brings up an interesting point about the non-availability of used bikes at LBS's. Since many shops are "dealers" for a major company (Trek, Specialized, etc.), perhaps they are prohibited by contract from selling used bikes? If all LBS's had used bikes for sale, it would probably put a dent in Trek's new bike sales...

It can be argued that leasing would INCREASE new bike sales for a couple of reasons: 1) consumers would perceive that they could afford more bike, and 2) when coming off lease, folks might swap in for new. In addition, it would not necessarily be the responsibility of the LBS to hold or sell bikes coming off lease :)