It's a fun idea.  As a gamer though, it doesn't look very fun.  I loved the game Ultima Online growing up, I like it inspires you as well.  I think it needs some serious work though like maybe a bit more should have been developed before release, if you could create a fun game-like Runescape or Ultima online, you might be onto something.  Not everyone wants to craft cities in Minecraft as well, so it shouldn't revolve around your game, plus your target audience will be mainly adults.  It's very awesome it's open-source, kudos for that!  I'll follow you.  Good luck.