An expansion that's been catered to be casual friendly; fun nontheless.
The dungeons are fun, and with the newly implemented dungeon and raid finder, it's quite easy to find a PUG (pick up group) and do them. The new ilevel stat helps players identify if their current gear and status permits them to enter higher and more difficult dungeons/raids. The monotonous heroics are back from Wrath, dungeons which are the same as normal, except they're reused so that players can farm them for gear and 'points' to purchase higher ilevel gear (which helps folks get into the harder dungeons/raids).
In conclusion, I would say that a lot of the hardcore/elitist folks have been giving disparaging remarks that cataclyscm has been catered to the casual market; I would disagree. Looking at a business perspective, Blizzard would want to make their game more accessible for current and prospective gamers. I personally believe that they're going in a right direction, you would want people to stay in the by having a fun, accessible game, but also not forgetting the hardcore players by giving them really difficult gear/mount rewards for their achievements.