I would love to have seen Walt as a significant piece to the puzzle as im sure you do. But to me it seems that since walt cannot be filmed as a young child again, the rational thing to do is leave him from the script in any significant way. Its a shame, I bet Damon and Carlton hated that fact too. On the other hand, he may be written in as 2010 walt. What does that say for Jacks attempt to change the past? hmm. I CANT WAIT!