I was going to bump this to the General forum, but I think the talent tree comment is worth addressing in the role forums, since it applies to class design.

1) We are changing talent trees, in some cases substantially. The major focus is pruning out boring but valuable talents that passively increase say damage or healing.

2) A secondary focus is to fix the clunky areas (e.g. warlocks having two conflicting range increasing talents). We're not going to remove old favorites or radically change the focus of the trees. You will definitely have to rethink your builds however.

3) Because you earn passive bonuses just for spending points in the tree, those fun, niche or utility talents won't seem as expensive as they do today. We want to create a lot more choices where you are choosing utility vs. utility. We want to see far more "cookie cutter" build guides that say "Spend the last 5-10 points where you want."

4) In some cases, trees will flat out get new abilities. These are in addition to the new level 81+ abilities.

5) You will get 5 additional talent points for the new levels.

6) We are not deepening the trees. This actually unlocks some interesting opportunities. For the first time, you can reach a 51 point talent and a 21 point talent in another tree.

I'll also add that for Lich King we just brought Naxxramas back and adjusted the bosses for 10 and 25 raid sizes. The Cataclysm raids are new content with new maps and new bosses. We're just trying to hit the nostalgia button with mentioning old foes like Ragnaros. Ragnaros may be back, but he's not in Molten Core.