Yeah they're announcing a surprising amount for this just being at Gamescom. I do in fact think that Blizzard knows they have to show a lot off, but I think this expansion has been being worked on since WoD launch clearly. Hopefully it shows.
I like the focus on classes they're talking about. I'm sure they will still be homogenized as fuck, but it's great that it shows me they want to make being a class a different experience than being another.