A DVD of season one will be released at the end of this year. The audio will be in  5.1 stereo surround sound mix for the first time, and there will be over over 200 minutes of special features, with an exclusive additional "Doctor Who Confidential".
 
Canada's Planet of the Doctor web documentary has been completed, check out http://www.cbc.ca/planetofthedoctor/
 
The next two seasons of Doctor Who are definite, with David Tennant signed up for both seasons. Billie Piper is now confirmed as staying on for at least the whole of the second season and Jack will appear in quite a few episodes, but not the first few.
 
There will be 13 episodes in each season, with the addition of two Christmas specials.
 
Season two won't be seen until next March in the UK.
 
Apparently the new doctor will have a new outfit (no great surprise) and we'll be seeing more of Rose's boyfriend and her mother.
 
Here are some working titles and writers for the second season:
The first block of episodes are to be directed by James Hawes, and consist of
The Christmas Invasion ("Episode X")
Episode 1 (no name yet)
and Episode 2: "School Reunion", by Toby Whitehouse;
 
Block Two, directed by Euros Lyn, and Block Three directed by Graeme Harper will be two and four episodes respectively, although it is not yet known exactly which episodes these will be.