There’s some interesting designs for the Doctor and Martha at comic book illustartor Ben Templesmith’s blog.
The concept art is apparently from an upcoming comic, and although the comic remains unnamed, the assumption is that it is a future series from IDW.
IDW’s current Doctor Who series are set to come to a close in the very near future, and there are apparently serials in the pipeline to take over from then.
Templesmith’s most notable works have been 30 Days of Night (which has spawned a major movie) and Fell. His other projects include the critically acclaimed serial Wormwood: Gentleman Corpse which he also writes, as well as Hatter M, and Singularity 7.