Sorry, I've just been watching more British television than reading comics in the last few days. I'll post something about how awesome Blue Beetle is soon, I promise.
Anyway, I just watched Martha's first episode of "Torchwood," and it has my wheels a-turning about what might be happening in "Doctor Who" this season.
First, I thought it was interesting that traveling through space and time physically altered Martha (and presumably, the other companions). We got a hint of that twice before, when Rose and Mickey were each said to have absorbed some kind of time radiation, which allowed them to reactivate the Daleks. This dovetails nicely with the recurring companion refrain, from Rose to Sarah Jane to Donna to Jack to Martha, that traveling with the Doctor is a life-changing experience, and one which doesn't lend itself well to a return to normal life. Now we discover that there's an actual physical mutation--no doubt due in part to the time-traveling energies, and in part to the various alien microbes they're exposed to. I hope this will get picked up in the "Doctor Who" season, and I can already see some story possibilities, assuming some of the rumors are true.
The other thing I picked up on is that Martha was hired to U.N.I.T. by a woman, who claimed she came highly recommended (which everyone assumed meant that the Doctor put in a good word for her). Now, I've never seen any of the U.N.I.T. episodes of the original series (though I'd like to--any recommendations?), but after a little research, I wonder if this means she was hired by Jo Grant or (more likely) Liz Shaw, both former companions of the Doctor, both (at least one-time) employees of U.N.I.T., and both prime candidates for a season that seems to be centered around the Doctor's companions. Consider that my prediction for the rest of Series 4.