The BBC just issued their press release for episode 12. They've done a pretty good job of keeping the title a secret until now. I'm not sure they've ever managed to keep a title secret until so close to the air date before.
Title and synopsis:
Doctor Who - The Stolen Earth Ep 12/13
Saturday 28 June
7.00-7.45pm BBC ONE
www.bbc.co.uk/doctorwho
Earth's greatest heroes assemble in a time of dire need, in tonight's penultimate episode in this series of Russell T Davies's Bafta Award-winning time-travelling drama. But can the Doctor's secret army defeat the might of the new Dalek Empire?
With battles on the streets and in the skies, the Doctor and Donna must brave the Shadow Proclamation to find out the truth. However, a fearsome old enemy waits in the shadows...
David Tennant plays the Doctor and Catherine Tate plays his companion, Donna Noble.