Of course you'd HAVE to have an old man living in a cave near spawn with a single wooden sword. "It's dangerous to go alone. Take this."
Not sure I'm too keen on having NPC out and about building things on their own though. For that I'd just as soon find a multiplayer server.
I wish there was a system for including player created content, ala Spore. Let players design a chunk, send it in, and the best, oh, twenty constructions are plugged into the next game update so that a few will randomly appear whenever you create a new world. I was in the desert digging sand out of a hillside yesterday thinking to myself, 'How cool would it be if I were to suddenly uncover a hidden doorway leading to a lost tomb?'
Or at least tweek the 'seed' system so that players can create structures as well as landscapes.
I go in fits and spurts with the game, I find. Haven't played it much for a week or two, right now, but I'll likely end up coming back to it before too long...
I find I'm the same way actually. Despite my complaining, though once I start the game I'm invariably there for the next few hours.
My Minecraft house starts to feel almost like a home away from home.
Oh, and for todays 'wish they were in the game', glass slabs, so you can build thin platforms with glass floors.
Been working on a treehouse for the last couple of days, and I was going to add 'tree blocks start to generate leaf blocks after a day or two' Just so I could fill in some gaps. But I did a Google search and found out about the 'put a block of dirt on a tree block then plant a sapling' trick. So now I can make uber trees!