The enthusiasm was of course originally generated by the students, and the initial investment (approximately $20 per computer) has been well worth it. Fortunately, I had already been teaching a game design, class and we had some grant funds to get Minecraft going. For support and ideas, I relied on the MCEdu wiki and the wonderful Google+ group for MC educators here in Vermont.
Many opportunities exist to utilize Minecraft in the classroom as a curriculum tool and can easily be found with a google search; 3rd grade teacher Jim Pike, for example, has been using MC to teach Common Core math skills. However, with the often overwhelming demands on today's teacher, finding the time to fit MC into the regular school day can indeed be a challenge.
For several years, our school has been running a highly successful afterschool enrichment program, so a Minecraft club seemed like a natural fit. Actually, I have found that incorporating MC into an existing topic can help keep the online activity focused on creating and building. In Amusement Park Design Club, students make marble roller coasters and K'Nex ferris wheels, and then create an entire park in Minecraft; in Electronics Club, students learn how to solder circuits and LED's and then make Redstone creations in their Minecraft world.
My biggest 'ah-ha' with Minecraft however, has been the opportunity for our students to develop and practice their social skills. Our program serves a wide variety of students, several of whom receive special services or who don't always 'fit in.' When they are all working together on a server, they must find ways to interact and build a negotiating process. They set the rules for themselves and also consequences for those who do not follow them. They are constantly sharing and asking questions and offering suggestions. The journey is not always a smooth one, but it is those very challenges that I think truly can open up whole new worlds.