Well no duh. We lost some skills, Gerk is on a long CD, our piercing debuff took a small nerf as did Blood for blood. There's been an across the board nerf to group buffs, selfbuffs and the role system change stole some goodies from everyone. Same thing happens in every mmorpg that has an expansion with a level cap, all classes become rebalanced for the new level cap.
Get to 70, get geared, learn new rotations. Things will be fine. We've seen initial data that shows DRG is in a good spot for overall dps. Nothing to be upset over.