Interesting on the Barbarian. In the article about playtest in December, they suggested the Barbarian would get a change to his AC, so as not to rely on heavier armors.
Checking out his AC, he's got a 17 (1 from level, 4 from +1 hide armor, and +1 dex). That adds up to 16. It doesn't appear that the Barb gets his secondary stat to AC like the other primal classes have.
The other threads have talked about weapon expertise, but I wonder if the +1 to attack doesn't come from the great weapon prowess of the goliath, and that weapon expertise (in keeping with 3.x naming conventions) = a bonus to AC when weilding a chosen weapon type.
Just speculations. I wish it was march.