Good god no! One of the reasons Facebook won imho is simply because you didn't have to go hunting for core navigation features for every single user's profile page. I do emphatically NOT want that with Github... write a website for your project on ghpages if you want it customized.
1) Most GitHub users are more tech-savvy (and often more CSS-savvy) than your average MySpace users, and
2) Most GitHub users put a lot of value in their repo pages,
this actually seems like it wouldn't _inherently_ be the worst idea, assuming the proper precautions were in place versus bad actors. Allowing each org to fully customize their git repo almost encroaches upon (or replaces?) project websites, which already has some overlap with README files (which aren't currently prioritized). Kill two birds with one stone by giving developers what to prioritize on their repos?
There is lots of value for me in the fact that all those project pages look alike. I can easily go to any project and immediately know where to look and click. This is useful for doing technical evaluation of projects. On Myspace the goal was to show individuality and creativity. GitHub is about the code.
