Doctorwho.tv has posted three pictures from the upcoming 50th anniversary special:

http://doctorwhotv.co.uk/daleks-return-…

The first thing you'll notice is the presence of daleks in the photo. But look beyond that, look at the decor of the room they're in; Gallifrey? Either that or a Gallifreyan ship. It could be a Time War flashback, but I'm hoping we get to see the Doctor return to his homeworld. It'd be fitting for the 50th Anniversary, don't you think?