I guess most of us agree: Studying Chinese characters is not so much about ability, it is about motivation, endurance and mental stamina.
The main thing that motivates people is comparison.
So one of the primary reasons why I use Skritter is its excellent progress page which allows me to evaluate my progress and compare different periods of time. This can significantly reduce the number of "lazy days" that most language learners are familiar with.
Motivating yourself by comparing different time spans of your own performance definitely works in the short run. However, in order to develop real long-term motivation, you need to get feedback, ideally by comparing yourself with others. On Skritter, the Twitter publishing feature is already a good beginning, but it doesn't go far enough.
I think it's time for Skritter to get toplists.
Toplists could show who studied most during a day, week, month, total; e.g. counting revised characters, learned characters, hours of work ...
Due to the different parameters, everyone would have the chance to appear on a toplist.
The majority of websites that try to build up motivation work with some kind of toplists, an example is the 百度百科 starlist (http://baike.baidu.com/starlist), although its aim is somewhat different, and a Skritter toplist surely wouldn't have to be as sophisticated.
Admittedly, a toplist could lead to bad incentives (marking characters as right although memorization wasn't really accurate; learning more characters than one is able to "digest" ...), but this should be less of an issue on Skritter than on other pages since I guess most Skritter users take their long-term performance seriously.
Individual user pages would be a great addition as well, especially if they allow users to display their usage statistics.
Given the statistics that you already have, toplists should be easy to code. Since some users may not want to participate, there should be an option to opt out. However, I generally assume most of us would be happy to appear on a toplist.