Never played or got interested with Minecraft, but isn't DS endgame kinda comparable in the sense that you build and explore just for the sake of it because you enjoy it?
From Julien Chieze review, the way he describes (while spoiling a craftable item that wasn't shown at all in promotional material, Thanks Julien :( ) the endgame seems very comparable to this, like you build and make better ways for the routes you initially passed without help, and then there is also the scoring system, where I saw that takin a new route counts in your score, and also the time difference between you new route and the shortest route possible. Seems like missions are highly replayable as your buildings and new stuff are taken into account when replaying missions, and simply creating new routes and transportation systems in the world map seems to be quite fun and serviceable for people still playing :)
Damn OT is up lol, I'm gonna miss this thread!