There were a few things that I was reading/doing recently which led me think in this way.
MS researchers published a paper where they explains how a torrent session can be transferred from a Vista to a NIC on the same machine. This NIC runs Linux on ARM.
A FreeBSD flavour that has only storage related functionalities. I downloaded the image for x86 and ran it under qemu. Checked the page on a browser. Except for a few, it was running almost the same functions that my laptop/TC was running.
We currently provide support for EDMS in a few organisations. However, their requirements are simpler. Alfresco is really an overkill. This can be simplified.
4. The High power - Low power boards
Yes. There is a bunch of such boards which consume very low power yet have reasonably powerful processors and fast NICs. I recently setup an always on home server using a VIA board and cheap USB drives. The system is running for days together without any complaint. No cooling, no maintenance!
FreeNAS is a nice solution. But I am little too old to learn FreeBSD now (Might correct this statement in future :) ). I am planning to make a Linux NAS server. Got a call from someone. Rest later.