2. Walt Has A Heart Attack
What if the end of all of this is Walt having a heart attack? His first threat was cancer, and he seems to have beaten that for the present time. His second threat was the meth empire, and he has escaped and cheated death more than a few times in his line of work. What if the real threat, all along, was his awful diet? Walt eats way too much bacon. You know it, I know it, and its likely that Walt even knows it. The White family eats large and full breakfasts much too often to be completely healthy. So, maybe the two birthday breakfasts that we see during the first part of Season 5, when Walt has eggs and bacon in the shape of his age, foreshadow his death via heart attack.