I believe that the statement: "bitcoin is new kind of money" passes the duck test.

Bitcoins function as money (they're a unit of account, a medium of exchange, and a store of value), and if PayPal started allowing Bitcoin transactions tomorrow I'm certain they'd treat them as Just Another Currency.

If you like, call it a commodity, but I think all you'll accomplish is confusing potential users who might think they'll end up getting pork-bellies delivered to their porch if they don't get rid of their bitcoins.