Making a feature-length anything isn't easy. It requires a lot of planning, time, dedication, and a large cast of supporting players. Hugh has been releasing documentaries once a week that go over everything from concept to development to preproduction, all the way to finish. These short films are extremely helpful to any aspiring machinimator plotting a large-scale project! For more information, check out the BloodSpell blog.
If you have machinima or movie suggestions from any MMO, please send them to machinima AT massively DOT com, along with any information you might have about them.