The German news magazine Der Spiegel claims that they have some
inside information from the investigation. Afaict with my knowledge of German the article says:
The first pilot was not in the cockpit at first when the catastrophic events started, but he came running in, shouting instructions.
The speedometer ("Geschwindigkeitsmesser" they write in the article) was iced over (I suppose this is the pitot tube, but aren't there several?)
The plane did a steep pull-up, not clear if this was pilot induced or computer induced
No severe turbulence preceded the catastrophic events