From my reading of the report I'd still think that a major failure was the cause of the accident. Sure, the crew were trying to control the aicraft to the bitter end; but so were the Alaska Airlines guys when their stab broke loose. They had zero chance. With any element of control, I'd expect a couple of partial recoveries, yet they went straight down.
I think that the investigators have some idea of what they are looking for. When the weather improves, I think that they will return to the accident site to confirm what they suspect.