This honestly stands as an idea that should have been started years ago.
I love the Lego games. Star Wars, Indiana Jones, Batman, they are unique versions of popular culture with their own story, feel and challenge. They aren't tough to beat and are genuinely engaging on multiple levels. It strikes me as odd that I never even knew I wanted them to build a lego MMO. The idea itself if just about perfect.
The main problem alot of people have with MMO's are the timesink, or the sandbox elements, or the content. Either of those three can make or break a game, but all of those are the basis of the physical lego blocks. Not only do you get legos to let your creativity run wild to express itself, you use them to pass the time. Mission accomplished.