GPS Tracklog mentioned that Blackberry announced that they are starting an 'opt out' service on all Blackberrys that will track them for traffic data a la Dash which was purchased by RIM. The best estimate for active Blackberry accounts in the US is 22 million.
RIM is making the data available to developers.
So figure as many as 20 million traffic probes are now available for someone to use. Given that Dash had relationships with both Inrix and Navteq for traffic and TeleAtlas for maps I have to think they will all have access to this data at some point for a price.