In the player profile it would be very good to have the rating histogram just like the one on the Topcoder.

Because of the way the rating system works on Topcoder, you can see a small bump just before the division change. Is there a bump on Codeforces as well? :)

I also have a feeling that the programmers on Codeforces are stronger on average. Such a histogram would be a good indication of that.