When Virtual Worlds Collide

While I try to stick with one MMORPG at a time, I know a few people who play several. (Where do they find the time? I'll never know!) However, I imagine I'll eventually leave my Warcraft avatar behind and move on to other games - where I'll start from scratch. However, this article on Wired suggests that the future may see the boarder between our virtual realities blurring. Are we going to be able to bring our Sims to Azeroth? Doomguards to Animal Crossing? Perhaps not specifically, but as more and more people flood into virtual worlds, it will be interesting to see whether the boundaries between them change.