Something similar to the world tendencies in Demon's Souls. I miss where Atlus would make the worlds more difficult with a higher reward or easier with less souls obtained. Also, how they made certain events only accessable during those extreme times.
On PC, do away with GFWL. There have been a couple of people I know, either on here or elsewhere, that have had issues with that platform. Also, don't lock the resolution and cap the framerate as this negates many of the pluses of gaming on PC.
Allow more than one control scheme for our controllers and KB/M(as if anyone really plays this game with KB/M). I can't count the times that I've rolled off of a mountain or into a pit when I was trying to jump over onto something else.