I believe that the new server software "Squeezecenter v7" is being finalised by Logitech prior to final shipping of the units and that this will probably be ported over to run on NAS units such as those from QNAP, Buffalo (Linkstations), etc.. by the very talented Squeezebox user community - see www.slimdevices.com
and the community / forums pages for more information.
I've been following the Squeezebox development for a long time now and have been waiting for them to release a SONOS type controller at affordable prices - so we're nearly there now! I just hope the quality of the Duet range is as good as the quality of the Squeezebox 3 which has always been so well reviewed (Wolfson DAC now vs Burr Brown on the SB3)...
A question to the WHF team though - when will they be able to review it - do they have access to an advanced release ?!!!