WoW released with 3 raids, difficult and requiring weeks.. no months of progression, each proceeding the previous in requirements at release. It took people a rediculess amount of time to clear all the end-game content and by the time they did Silithus came alive with AQ 20/40
WoW released with a more "complex" PvP system in which Rank and PvP currency was required and you couldn't even dream of having the full sets(it was in fact impossible) within 1-2 weeks of release.
I could go on and on. I'm not a WoW fanboy, i've played it for 7 years and can't stand it - what i am trying to say is the game is almost none existent for content at 50. Granted there's an amazing story for you to complete other than that, pvp sets are acquirable in a few days and people have already cleared the only raid out there.
Please note i'm talking about WoW at release.. Now it's a p*sstake in difficulty and clearing deathwing took all of.. 3 hours since patch release.