The next time we see each other, I'll talk about your mother

There are two times Jon's mum is brought up in this episode. 

The first time is when Jon says bye bye to Ned

Ned is sad. Do not think a Lord will have such emotions over a commoner. 

So, It's not Wylla. It has to be Lyanna or Ashara.

So he has to continue keeping the secret, or he cannot tell him as long as Robert Baratheon is up to.

So is he just stalling? Does Ned have some other plans? Is Jon's mother alive?


A little later, Robert asks Ned about his bastard's mother. 
Then Ned's slight nod when Robert confronts him about what Rhaegar did to his sister.

The discussion of Jon's mother leads to Targaryen discussion... so... Im thinking Lyanna not Ashara.