Thesis is a theme and framework for the wordpress platform. Andrew had used it before for some client sites and liked the features that it contained. In a nutshell it gives a wide range of controls and options through the wordpress admin interface, so that a user has more control over their site with out a developers assistance.
Those of you in the area who are interested in all things web related should consider joining Dennis Lembree and I for a meet up in Ann Arbor. It will be well worth your time.
As designers we know that a web page is not pure aesthetics, there is both form and function. However this is a difficult concept to grasp and separate for the average person. It is very easy to get hung up on little details that may or may not be important or relevant to a finished design concept at hand.