Not from your area, but my brother recently needed to get a CableCard on the Plainville system. The new mandate lets him pick it up at the local Comcast store, but here's the rub.
According to them, to activate it for more than basic channels - say HBO - you need to have a truck roll for them to do the pairing. Needless to say he complained that it is pointless to let him self-install something that only halfway works, and they waived the truck roll fee.
Also, this was right at the beginning of the self-install period for CableCards, so perhaps it has improved since then.