Yeah, every boss I've researched so far has different info from different sources, so we're just gonna do our best. Fatboss videos are all old as shit from Alpha, Icy Veins is not generally much better, and very few of my other regular sources have anything substantial at all yet. But, that's pretty normal for before stuff is released, and it's what makes the first week of raiding so interesting.
As far as class info, the druid stuff at least looks pretty up to date on Icy Veins, but I could be wrong. Besides, I haven't been able to find anything else worthwhile for druids, anyway.