At this point they've tainted Hank with drug money too, I wouldn't be terribly surprised to have a Reservoir Dogs style three way gun showdown with Hank, Jesse and Walt. Walt and Jesse seem destined to have some sort of ultimate falling out. Hank hasn't been in the mix throughout for no reason either.
I can also see Walt engineering his own death and taking the cowards way out, he has continually made bad decisions throughout the show and ruined everything he's touched, I could see him doing a suicide by cop at the hands of Hank and pushing him totally over the edge into madness in the process for his own selfish reasons to avoid paying a penalty for his sins.
Regardless, I'll be tuned in through the last seconds of the show, Breaking Bad has been masterful thusfar.