A somewhat related thought: Do any of you guys get pulled into a game due to seeing the expansion box on the shelf? I typically look at it and figure I'm not going to drop money for the main game plus expansion to get into a game I'm 6-12 months behind on. Plus, I typically look at games with expansions as old and not worth my time if there are newer alternatives out. That's just me though.
If something looks interesting, but not au$80 worth of interesting, I'll sometimes pick it up a year later with the Stuff + Expansion Uberpack. That's if it still looks interesting that much later. And usually, when the Stuff + Expansion Uberpack drops to au$50 -ish or EB has a clazy sale..
They mention "significant expansion" to the cooperative play side of things, which to me means, a focus on more content and dynamics for the PvE player.