Well, here's the trailer for "The Waters of Mars"
Looks interesting, as someone said about PotD, this too looks rather classic esque.
Now there's not much infor available right now apart from the following:
Companion: Adelaide (Lindsey Duncan)
With Peter O'Brien and Sharon Duncan Brewster tagging along, as well as - apparently - Ood Sigma.
Now what I'm wondering is if there'll be any connection to the Ice Warriors, as within the Whoniverse is is established that they are indeed Martians. Even in the classic series. Obviously this is going to be set in the future, but could they still be around?
So go on, speculate!