Gus will die at the end of this season, possibly Mike, too.
Mike will definitely die by the end of the final season.
Walt’s cancer will become an important factor in the upcoming season. It’ll be terminal, and we’ll find out by this season.
His transformation into a crime lord will be nearly complete by the end of this season, and at the start of the next season, he’ll be well on the path to becoming an all-out, irredeemable sociopath who’s driven by bitterness that his life is coming to an end. He’ll be killed by Jesse or Hank, maybe Jesse.
Hank will find out that Walt is Heisenberg in the last few minutes of this season. The next season will be a cat-and-mouse game between him and Walt.
He’ll spend the remainder of the series struggling to reconcile his desire to catch Heisenberg with his loyalty to his family. If he does kill Walt at the end of the series – and I’m going to say it’s a coin-flip between him and Jesse doing it – he’ll do so with a lot of anger and reluctance, and he’ll have come close to ’ breaking bad.’
At the end of the season, with Walt’s secret exploded for everybody to see, Skyler will end up losing custody of Holly and Walt Jr. She’ll go to prison. Her children will both wind up with Hank and Marie. Walt Jr. will be turned jaded and misanthropic by the fallout of his father’s criminal activity; he’ll be cold and angry, even more than most teenagers.
Jesse will ‘break good’ and settle down with Brock and Brock’s mother. He’ll be a little worse for wear for all that he’s gone through, but he’ll suck it up and act like a grown man and a responsible adult.
Unless, of course, Walt kills him. That’s a real possibility, I think. Him, Hank, and Mike will all be in danger.
It’ll be business as usual for Saul. Without Walt and Jesse, he’ll go back to being a shady criminal defense attorney.