Based on this interview at GamesCom, it appears that Blizzard may be excited about bringing 5-man dungeons coming back a bit more. With MoP, I personally was disappointed that the scenarios tended to be more useful (while at max level) than dungeons. It sounds like the focus will be moved back to dungeons (regular, heroic, timewalker dungeons (aka downscaled older TBC dungeons)).
Personally, I loved the dungeon experience in Wrath. You'd level up a little bit, then end the zone with a quest to run a dungeon. In Wrath this was hard because you had to spam chat to gather people for the dungeon. Remember, no Random Dungeon Finder back then. Looking at some of the beta videos, it looks like that is what's going on. For example:
What do you think? Are you going to miss the quick scenarios?