It's not really a bad idea, scenarios where okay in WoW for the most part and it was something to do while waiting on a Dungeon Queue.

The bad thing though is that Blizzard seems to think scenario content is the future of WoW which resulted in Panda Land having less heroic dungeons, and I've heard Warlords will have either around the same number or possibly less (I could be wrong, feel free to correct me). Anyway what I'm trying to say is adding more content or something else to do while waiting for my 30 minute dungeon queue is nice, but I'd hate to see the development team for this game say that they can make scenario content or dungeon content, not both.