I recently came across this issue as well and I wasn’t finding a lot of support for it, so I quickly forgot about the problem. A few months later I saw a better example of the smooth scrolling so I went in and dug around the JavaScript files they were using and I found that they were using a jQuery file called NiceScroll.
I believe this is what we’ve both been looking for- simple smooth scrolling for divs, iframes or whatever, much like the iOS scrolling.
http://areaaperta.com/nicescroll/