According to many sources, Stephen Thompson's upcoming Series 7 episode is called Journey to the Centre of the TARDIS.
Also, interestingly, Matt Smith almost let this one slip in a Q&A session back in August. He said, "Can we talk about Journey to the-" before being cut off by Caroline Skinner.
Below is the article from The Sun with the rumour:
[Ashley Walters], who has a guest role in the episode Journey To The Centre Of The TARDIS, said: “I almost got sacked on my first day as I tweeted a picture of me. I was lying on a sofa on set in Cardiff in my space outfit and put the picture out there with the caption ‘Space’. Five minutes later I heard a banging on the door and it was the executives telling me off as they have to keep everything a secret. I then saw all the signs on the doors telling people not to tweet photos.”Ashley Walters is playing one of trio of brothers, who are an intergalactic salvage crew.
