Do you mean the batch of 6 episodes that went out as Series 2 in the UK? Those are on the DVDs that are available now at Target, and will be available everywhere on Oct. 26th.
If you mean the second batch of 13 filmed - i.e. this episode onward which premieres next month in the UK - no idea. I would assume it'd get a DVD release in the States, too, eventually, but who knows when. (Also pulling for the chance that someone will decide to air the show over here!)