My thoughts on this topic are as follows: I think that places reminicent of past games are a must. One thing that absolutely needs to be in Mother 3 is a monkey village! You may not remember (or you haven't played the game), but in Mother 1 there is a monkey village in the desert, and of course we all remember the wonderful gift-giving game we were forced to play in the underground village in order to get to Talah Rama in Mother 2. There was also the community of monkeys in the deep darkness. It's obvious that Itoi likes these quirky villages, and there's got to be one in Mother 3. As for other stuff, I'm sure he'll add a Magicant, which is another thing reminiscent of both series. From what we've seen already, I don't really have anything to comment on. The village looks rather typical to a midwest town. The forest... is a forest. Anyways, I don't have many thoughts on the places we've seen so far, I just see what could be there in the future.
Enough of my blabber, on to the rest of the fanthoughts.