While the Burning Crusade proved to be a major dissapointment, save for a few interesting features and instances, the Wrath of the Lich King seems to have made quite the comeback for Blizzard. While the game still lacks many things-- since Blizzard aim to please the masses, the deficulty level and required intelligence for playing the game has been continuing degrading over the years. While the Wrath of the Lich King does not rectify this issue, it does add some new exciting things to the game; such as the Death Knight hero class, barber shops and the frozen wastes of Northrend (a landscape that has been much better composed than Outland or even Kalimdor or the Eastern Kingdoms in my oppinion).
Graphic-wise the game is still stumbling behind, not at all living up to the big name Blizzard has, as the supplier of billions of WoW-addicts, but again this seems intentional; as Blizzard wants most possible people being able to play the game. Again, I'd like to use this oppotunity to remind Blizzard that they seem to have cast Warcraft lore to the winds in their creation of Wrath of the Lich King, as the game 'balance' seems more important to them than the lore.
As any other MMORPGs, Blizzard can't really be blamed for the stupidity of the people playing the game, but it would be nice if RP servers actually involved any roleplay: but Blizzard doesn't seem to care much for 'eccentrics'.
All in all, Wrath of the Lich King lives up to the standard of WoW, but does not exceed it. Blizzard seems to have a way with the masses, and the few people who care about lore and graphic are not a priority to Blizzard, hence I doubt we'll see any improvement in that department. Nor does the game offer any intellectuctual challenges. If you're looking for a neverending fantasy-world with hundreds of creatures to slay and items to wear, or if you're an hardened WoW addict, Wrath of the Lich King is definitly something for you; as long as you don't expect more of it than it is... ...