The answer to this question is NO, there are not usually any cabs around that Bart station. AirBart has been somewhat better as of late but, when it's not running, expect to see locals asking for $20 to get you to the terminal in their personal car. I would not advise accepting this offer.

It's also nice to know that AirBart now accepts cash. It seemed that, for a while, every time I got on to AirBart the driver was threatening to call the police on someone who deposited cash while the driver sat reading the paper. Or, the driver would send someone out to the vending machines to buy a ticket and leave just before they could get back to the bus. AirBart, along with nearly everything associated with the Oakland airport, is truly a 'unique' experience.