Steven,

Just to piggyback on this post, JomSocial templates are specific to the component and are found under the com_community/templates dir. The default one basically consists of all the necessary files needed to run the component (ie: email templates, stream messages, friends display, profile display), then if the user wants to customize the output, style, etc, they create a new jomsocial template (named anything other than default) and similar to the joomla template override function, they would just copy the file they are looking to change over into the new template folder and it would override whatever is in the default folder.  jomsocial updates would not affect anything inside of the template folders... same concept as the general joomla template overrides, but specific for jomsocial and located in a different location...

hope this helps explain things for the future...