Absence of end-game content : the downfall of every MMO.

[zdub303]

Once you got your gear, all you had to pick from was Onyxia and Molten Core. That was endgame in Vanilla until Patch 1.6, which added Blackwing Lair, over a year and a half after launch.

It was about 8 months or so, not a year and a half. Nov 2004 release and 1.6.1 was July 2005.