Interesting reading all this, I am in the same boat, needing a nas for home use but also a print server and also for using squeeze centre after xmas. The nas systems cost a lot of money for something that could do this, no expandibility and low end systems suffer from poor cpu's on squeeze centre.
looking at a windows home server too based on an intel atom 330, with 1.5tb samsung f2s in raid. Power consumption is tiny against anything else. Apparently each w used equates to £1 extra saving a year (rough guide) so the savings add up quickly on using the atom.
I already have a HTPC and gaming pc, and a windows home server along these lines seems more appealing than off the shelf NAS. Cases for an itx system seem limited on h/d capacity
Please let me know which other components you will go with for your home server. I'm looking for a nice case for it at the moment.

