i'd love to see more fluid mechanics (like the tarpits).
some form of magic would be awesome!
i'd also love to get a bench that lets us alter old armor to make it viable in higher tier biomes. lnot just a simple upgrade to the armors lvl. after awhile that troll armor is useless, as the danger just outpaces the upgrades benefit. but if we had a sewing bench or something that would let us alter it's properties. better yet the artisan table lets us infuse older armor with magic properties that make it competitive with higher tier armors.