I think that part of the reason that Kara was so awesome in BC was due to the fact that it was the perfect entry raid. We have not had another entry raid like that.
Wtf ever happened to factions associated with dungeons too? The Kara ring upgrade from rep was an awesome idea and I have no clue why they scrapped it.
It should not be that hard to make a great dungeon. All Blizz has to do is look at Kara and Ulduar then make something similar. Not to bash Firelands because it has not been seen by most, but I really like indoor raids. Fire? Really? Fire is a real life hazard and if I wanted to fight fires I would have joined the fire department. Last I checked there were not any jobs irl that focused on killing old gods, psychotic ghosts, or dragons. No, Ghost Adventures does not count.