I just pushed out a very simple blog theme for Community Server to my downloads page.  This was part of an exercise of mine during the process of writing a chapter on theming for the Professional Community Server book.  The theme is nothing fancy, but it does show you the power of CSS and Community Server.  All of the CSS required for the theme weighs in at a whopping 1kb :)

This can also serve as a basic example for how to create a blog theme in Community Server.

Here is a screenshot of the little bugger...