A rare game that gets even those that have put their gaming years behind them back into it.
It would be hard for any other company to have the ability to spend this much time and put this much polish into a game. Given the long development time and the relatively few changes being made from the original and thus far only the one campaign. Guess that's the luxury you get from developing the cash cow that is WoW.
Duke Nukem Forever had a longer development time, but a sadder ending.
Team Fortress 2 from Valve had a similar development time and has had over a hundred patches since release, in addition to a fair amount of media developed outside of the game.
It's true that both have had significant backing bankrolls. However, you can also look to some indie 'studios'. Cave Story was a one man project that took 5 years (of spare time) to complete, and is often lauded as an indie star. Dwarf Fortress has only ever had one programmer (who is now supported by user donations), and probably deserves noting even if it doesn't quite attain any significant degree of polish.
It would be hard for any other company to have the ability to spend this much time and put this much polish into a game. Given the long development time and the relatively few changes being made from the original and thus far only the one campaign. Guess that's the luxury you get from developing the cash cow that is WoW.