I bet Walter will start a new family with Jesse. He will guide him through rehab, and continue to do business with Gus, who might feel a new sense of security after realizing that his new supplier might be protected from getting busted because of his marital relation to the DEA. Skyler left, and considering her tolerance to breaking the law is at such a low threshold, i cant see her coming back. Walter will use his money to expand into something much bigger, something that he got cheated out of when Gretchen capitalized on his research and started billionaire pharm company Gray Matter Inc. I am most interested to see how Jesse recovers from the most severe emotional blows; Jane dying, heroin addiction coupled with Meth relapse, the shocking and sad death of Combo, his family abandoning him, etc. Tragic character. All speculation!