As recently announced, NASA's in the planning stages of crafting their own MMO. Action Trip has commented nicely on this with their comic 'Pigs in Space'. World of Warcraft layers transparently over a trip to what appears to be Mars, with humorous results.
Something I love about this comic is the astronaut gamely going about his grinding duties; he seems to actually kind of enjoy it all. Also, maybe it's an orc in that suit -- the planet looks like the Valley of Trials, especially with the boars there. Go check it out and enjoy!