We'd heard in the past about Vin Diesel being among the list of actors and general high-profile people who play, but this does rather seem like it might confirm our suspicions.
It makes sense, if you think about it, that actors might enjoy immersing themselves in a virtual world, where, to some extent at least, they're playing a role. Reading the most recent 15 Minutes of Fame, with actor Jake Stormoen, the discussion of escapism and a world to hang out in on long shoots in strange places, it makes even more sense. Every time a high-profile person tells the world about their love of WoW, it gets a little less stigmatized, a little more accepted. It's good news.