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In a "BlizzCon Exclusive", World of Warcraft lead producer J. Allen Brack revealed that yes, there will be an expansion pack following Cataclysm, even though the developers don't quite know what it will involve at this stage.
We're currently a little over a month away from seeing Cataclysm hit stores, and Brack explained that when Wrath of the Lich King was at this point two years ago, the WoW team started to "coalesce" on the ideas that would later become Cataclysm.
This time around, the team are a little less sure than they were then, but they have started brainstorming ideas and chatting about what would be cool to include.
Jay Wilson, Game Director of Diablo III chimed in that "I bet there will be a Diablo III expansion too... BlizzCon Exclusive!" ...we'll see how that one pans out.
I like video games, fishing, Depeche Mode, long walks on the beach, writing discussion papers and cups of tea. Not necessarily in that order.
Jimmy the Geek