Much like the property market, this tantalising titbit is all about location, location, location.
In a video tweeted by the Doctor Who official twitter page and featuring Pearl Mackie and Matt Lucas, you can clear see a very familiar location in the background as the pair send their regards to the Welsh national team at the Euro ’16 football tournament.

A special message from @Pearlie_mack & @RealMattLucas to the Welsh national football team!#MadeInWales #DoctorWhohttps://t.co/oZ0D1v4K7J

— Doctor Who Official (@bbcdoctorwho) 6 July 2016

As you can see, we’re pretty sure that the pair are filming in the Wales Millennium Centre, a concert hall, arts centre and theatre in Cardiff Bay that has, in the past, often doubled as a filming location for Doctor Who, so, as the Radio Times speculates, could we be seeing the cast return to the site of a previous adventure?
In the past the WMC has stood in for the Musée d’Orsay in France in Vincent and the Doctor and two different futuristic hospitals, the cat hospital in New Earth and the time stream-accelerated quarantine in The Girl Who Waited, and, yes, it’s a bit of a stretch, it’s also the site of the rift in Torchwood. So could we FINALLY see the return of Captain Jack? Are we heading back to Torchwood Three?
Of course, the TARDIS could just be stopping of for a refuel or perhaps some big, bad monster has crept through the gap in space and time? While we’ve heard nothing of John Barrowman’s involvement, it’s a tantalising prospect indeed.