Amahi makes a home server solution of sorts, which I had never heard of previously, but it looks interesting:

Amahi is software that runs on a dedicated PC as a central computer for your home. It handles your entertainment, storage, and computing needs. You can store, organize and deliver your recorded TV shows, videos and music to media devices in your network. Share them locally or safely around the world. And it's expandable with a multitude of one-click install apps.

And now they're throwing out a bone to Windows Home Server users who are disgruntled over Microsoft's decision to axe Drive Extender in "Vail":

Many users are now looking for a WHS alternative.

Amahi, with it’s implementation of Drive Pooling based on Greyhole, could be an ideal alternative for many.

Certainly, it's something to explore. 

Thanks to Lorenz G. for the tip!