Aegon? (spoiler)
Why would Lyanna name her son Aegon when she knew that her husband already had a son with that name? I know that both Dad and the older Aegon are dead by the time she gives birth, but given that Ned and Howland come directly to the Tower of Joy from King's Landing, it's entirely possible she doesn't know about the older Aegon's death.
And even if she did know, it still seems a little peculiar, because it's not like this is Ancient Rome, where everybody gave their kids the same name. Giving your child the same name as your recently deceased stepson would seem rather cruel to me if I were the parent of both kids. (That could just be me though.) Is there some sort of prophecy she and/or Rhaegar are adhering to? Did she or Rhaegar believe the next Targ ruler HAD to be named Aegon, no matter what?
(And let's not even get into the fact that Older Aegon is supposedly still alive in the books. That just makes things even more confusing.)