This came up in a game last night where the skald in our group was giving out his inspired rage. My hunter and dog are both allies, but there was confusion in the group as to whether my dog is affected.
Personally, I'm of the mind that the dog is an ally, and with no real disadvantages to speak of in accepting the rage, should totally do so. Obstacles I encountered were along the lines of "Well you wouldn't be able to call him off after" and "He's not smart enough". Go figure, an argument for being too stupid to rage!
So were there any posts in the playtest regarding this? What about summoned creatures? If a bring in a flock of eagles, are they allowed to become angry birds? Who decides whether they do, me or the GM?