My main goal is to access music and videos from my NAS: it has Firefly and UpNp software but ATV can't see it natively; why Apple insists on only 'linking' the device to computers running iTunes is beyond me, especially now that they have done away with the DRM.
I'm at a loss as to why Apple hasn't developed a home media server. It seems that more and more households have multiple computers (all running iTunes) that each have multi-gigabyte libraries. It seems like there is an obvious market for a small device that would hold all of the household's music/movies/photos, allowing portions to be synced to individual computers, serving media to ATV's and Airport Express', with redundant backup.
This is what I thought the Mac mini Server would offer - Apple just needs to write an iTunes Server (and iPhoto Server) app...