Yes, LinuxMCE automatically maps samba shares for all the media types, and can provide general data storage. UPnP is also exported as well....
You'll find this system is a whole house solution, the first of its kind, and as such, you must set it up in the recommended manner.. two NICs, one NIC going to the modem, the other, to the internal network. The core will then provide file serving, gateway, firewall, VOIP, media director booting, and plug and play operation of NAS, networked tuner, IP phones, etc.
-Thom