Hi Teresa,
I have also have a MS live site (
http://virtualassistantcompany.space...m/default.aspx) and it was really easy to use.
I don't think they will be charging for it anytime soon since they are trying to compete with Google in the online application space. Not to metion all the integrations it has with it's other MS prodcuts. I just started building mine so I have not yet used the shared file area.
I'm actually using the space as a libray for my clients; I will we creating a link from my website to the MS site.
Good Luck!