TypePad People List is another way of saying FOAF (Friend Of A Friend). Basically, it means you would like to be added to my list based upon things we have in common. It builds a social network, of sorts.
My People List could be utilized to share like interests with each other. When you look at my About page it shows certain things that I take a strong interest in. If this is something that interests you then by all means ask if you want to be on my list.
As an afterthought, I can see how this might be used in Genealogy to link people together that are researching the same surname, locality, or topics like Adoption, Cemeteries, etc.. You could compare this to some of the existing Genealogy Message Boards like on Ancestry.com. The main difference can be realized by understanding the original concept of FOAF and what its purpose is. To generalize it; its a way to "semantically" communicate with computers, Web sites and any other data sharing technology. This way there is a non-proprietary method of communication that enables the "linking", as it were, of information that is related. Therefore, I can foresee that Message Boards will become a thing of the past, just as Blogs are rapidly replacing Web Sites. The Blog technology has been coined as Web version 2 or WEB 2. Whereas, most peoples experience with it is WEB 1. This is a huge change in the Internet world, and it may be time for all of us to seriously consider embracing it, as it will be the norm in a very short time.