The only thing I can say I'm really excited about is new worlds to see and the story. I'm skeptical but keeping an open mind until the beta about the changes to subclasses and perk trees, fixed rolls on weapons, 4v4 crucible, new weapon loadouts(primary, primary, "power"), in game lore, and how pve and raids will be now to work with the new weapon loadouts. The only thing I'm really upset about is the loss of TTK subclasses but I'm sure we will get them back later in a dlc.