I've been re-reading George R. R. Martin's Song of Ice and Fire series for the last couple of months. I took the first one on my Pittsburgh trip and got sucked in all over again ...
So, I got to thinking about the mystery of Jon Snow's parentage ....
.There's a continuing theory that Jon's parents are Eddard Stark and Ashara Dayne or some other now dead woman. I'm beginning to wonder if Jon isn't the son of Eddard at all.
I think Jon may be the son of Eddard's sister, Lyanna and Prince Rhaegar. It would explain the secrecy around who Jon's mother is. It explains why a) Lyanna was found in a "bed of blood" (she died while giving birth), b) why she would have forced Eddard to "promise" her something and c) why Howland Reed is the only other person who knows who Jon's mother was, since it was only Eddard and Howland who found her. There's no indication (thus far) of how long she was "held captive" by Rhaegar so she certainly could've been there long enough for her to get pregnant and give birth.
Anyway, just wanted to put that down so, if the man ever finishes the series, I can say "See, I was right" ... or be embarassed that my theory didn't pan out.