Sherlock, Mycroft and 'the other one'. Could there be another Holmes brother?

As Planet Earth anxiously awaits the next series of Sherlock, could it be that there might be another Holmes in the family that we don’t know about? Our first introduction to there being another member of Sherlock’s family came when older brother, Mycroft Holmes (played by series co-creator and writer, Mark Gatiss), kidnaps John and offers to pay him to spy on Sherlock out of brotherly concern. It wasn’t until the first episode of series 3, that we were introduced to Sherlock’s parents (played by Benedict Cumberbatch’s real-life parents).
The Holmes family

While both Gatiss and co-creator, Steven Moffat, have remained pretty faithful to the original work of Arthur Conan Doyle, the decision to introduce Sherlock’s parents was a pretty off-the-wall decision. According to Gatiss, this is a first. “I don’t know if Sherlock Holmes’s parents have ever been shown [in a dramatisation] and it felt like the right thing to do in the third season, to be even cheekier. Why not?” Along those lines, could Moffat and Gatiss be toying with the idea of introducing another Holmes brother?
Shelock, Mycroft and  The Other One

Hinted at by Mycroft in the series 3 finale, “His Last Vow”, when he said: “I’m not given to outbursts of brotherly compassion. You know what happened to the other one.”, this would be a total deviation from the original works as Sir Arthur Conan Doyle’s Sherlock Holmes stories make no reference to a third Holmes brother. Of course, the Internets exploded almost immediately with the suggestion that Tom Hiddleston (Thor, War Horse, Midnight in Paris) should be considered on the outside chance that this potential is anywhere near Gatiss or Moffat’s mind palace. Speaking to an audience at a recent Q&A in Brazil, Gatiss did seem to have fun with the thought. “Tom would be wonderful in Sherlock, I’ll ask him if you like. He then added, “Well, it is an internet rumour so it must be true. We might as well just wait and see what happens.

I’m up for it, how about you?

In: Actors/Actresses,Drama,Mystery