I think MySpace ultimately represented the final form of the essentially unlimited customization of the early web. The terribleness of MySpace pages was, I believe, the catalyst that pushed the design trend in the opposite direction, resulting in the "standardized array of fields" as popularized by Facebook.

That said, given the cyclical nature of design trends, I strongly suspect that we'll eventually start to see a gradual shift back toward customization, hopefully avoiding the ridiculous excesses of the MySpace era.