From the discussion, SPOILERS: Theory on Jon, my interest in my epic absurdity of The Grand Unified Theory of Every Ice and Fire has been rekindled. The terrible thing is that I cannot find the references I made to it a few years ago. Soooo, since this is the place for conspiracies... here goes.
The entire purpose of my never posted, never completed, and almost incoherent Grand Unified Theory of Everything was to unite the theories of The Dragon has Three Heads, Jon's Parents, The Valonqar, The Younger and More Beautiful Queen, Azor Ahai Reborn, The Prince that was Promised, The Stallion that Mounts the World, and The Song of Ice and Fire. I'll try to sum it here succinctly.
If Aerys raped Lyanna and Joanna, then Tyrion and Jon are Dany's brothers... this means Three Heads of the Dragon.
If Aerys raped Joanna, then Cersei is Dany's sister... this means the younger and more beautiful Queen could also be the Valonqar if valonqar is gender neutral the same way that Aemon figured out that prince is neutral in TPTWP.
If Aerys raped Lyanna and Joanna, then Dany and Jon, if not Tyrion too, were born amidst salt and smoke... they could be TPTWP.
If Aerys raped Lyanna and Joanna, then by killing their true loves (either literally or metaphorically) Tyrion, Jon and Dany are all candidates to be AA Reborn.
If Aerys... err, I cannot make anything out of this relating to the Stallion.
Jon already seems to be Ice and Dany already seems to be Fire. If Tyrion's their brother, then I don't know what that means.
I admit to some cons for the GUT. First, to reveal this finally in A Dream of Spring might feel like deus ex machina. I hate deus ex machina. Second, GRRM is more intelligent than me... could I really have figured out the entire story? Highly unlikely. Third, how many hidden bastards, Targ or Baratheon, can there realistically be? Fourth, GRRM likes red herrings.