Doctor Who on DVD in US?

They've released two new-to-me David Tennant-as-the-Doctor DVD episodes as single DVDs. I'm wondering if anybody has a sense that they'll release the other last shows he's in singly, and then release the shows the new actor as Doctor is in as a season box set? (Hope you followed that. :-)

I bought the two DVDs (and just acquired new seasons 1-4), but now I'm worried if I buy the next box set, I'll be duplicating my purchase.

Anyone have the scoop? Or an educated guess?

Renee, who's reserving judgment on the guy replacing Tennant until she actually sees him in a few episodes

I checked Amazon.co.uk and the last 3 specials (Waters of Mars and End of Time parts 1&2) will be released together on January 11 as Doctor Who: the Winter Specials. For those who haven't already bought the first two, all 5 specials will be released in a box set at the same time (title: Doctor Who the complete specials).

Amazon.com lists release date for the complete specials as Feb 2, so I assume it will be the same for Amazon.ca but I've been watching Amazon.ca and haven't seen a pre-release listing for it yet. Or any sign that they're releasing the winter specials on their own.

At least it looks like Waters of Mars and probably End of Time will be released singly, and since they'll be gathered into the complete specials, they'll be separate from whatever they bring out with the new doctor.

Thanks, Renee
(who works at a bookstore and makes sure we keep the Doctor Who books in stock :-)