Radiostorm has begun to stream radio to mobiles. Well via GPRS this is burning cash, via GSM it's killing your sense of hearing. But it seems they have made their claim when mobile connections get cheaper.
However it seems very tricky to produce some profits with the plain online radio business model. The ISP bills are enormous, even if you struck a deal. Plus you pay the fee for sending licencensed music. Advertisers haven't really ventured into online radio, so how to make some money?