Thinking it over, I also found that I expect several additions in any expansion for any games: some sort of new landmass to explore, new gear to wear, and usually some new mechanic or skill for character development. In WoW, I'd certainly expect a level cap bump too, though I'd grumble about powercreep in most others (don't go getting any ideas, Guild Wars 2)!
Let's put aside quibbles over the line between expansions and patches today and just focus on expansions. What, specifically, do you expect out of a content release that a studio labels an "expansion"?
Every morning, the Massively bloggers probe the minds of their readers with deep, thought-provoking questions about that most serious of topics: massively online gaming. We crave your opinions, so grab your caffeinated beverage of choice and chime in on today's Daily Grind!