This data set doesn't tell me too much.
Vehicle miles per vehicle has been roughtly flat for a decade. The data for vehicle registrations is annual so we won't see any change in 2008 for a while. My guess is that VMT per vehicle will go up in the next few years as the fleet size declines and family/household members share fewer cars.
As far as VMT per capita goes, I think it is a slightly trailing indicator of economic activity. That the rate of decline appears to have stopped increasing is
good news less bad news for the economy. I'll try to compare VMT to petroleum use in the next few days.