A few online retailers are now listing the next few Doctor Who DVD releases, as confirmed by BBC Consumer Products.

The Krotons - Featuring The 2nd Doctor - 2nd July 2012 - £20.42
The Greatest Show in the Galaxy - Featuring The 7th Doctor - 30th July 2012 - £20.42
Planet of Giants - Featuring The 1st Doctor - 20th August 2012 - £20.42 

Further details are coming soon, together with a full breakdown of the special features.

[Source: BBC Worldwide Consumer Products; Play.com]