The new Xbox Experience will be released late fall. But here is some news for the Games Played tracker. By selecting your Gamertag, you will see a number of slides behind that Gamertag representing the games you own. The first slide will represent how much Gamerscore you have and then after that how much maximum out of your game collection is achievable. Below that is also displays how many achievements you have and how many are possible to get still out of the games you have played. Pretty cool to know! Also for as many games you own, you will have that many slides.
Source: Joystiq