Had a little hunt through Amazon.co.uk last night, and if you look hard enough there are all manner of things planned to be released for the 50th Anniversary year. To date, I have found 3 different 2013 calendars. The official one which is released on 30th August; and another whose provenance I'm not sure about - think it is American and it is for 16 months (i.e. the end of 2012 as well as 2013). There is also this, which is a proper anniversary one:
In October 2013, there will be an audio CD release called "50 Years of Doctor Who at the BBC" which has Anthony Head's name attached. It is priced at a whopping £100.
There are also a great many books, but there is so little detail it is hard to say if they are official BBC releases or independents. How about Mike Tucker's "The Silurian Gift" released on 7th February and priced at a very reasonable £1.00?
DK Books are releasing "The Doctor Who Character Encyclopedia" on 1st April.
For US fans, you might like to check out "The Doctor Who Franchise: American Influence, Fan Culture and the Spinoffs" by Lynette Porter released on 31st January 2013.
If you have the time and the patience, do have a good rummage. (Remember - other on-line retailers are available...).