http://blogs.msdn.com/b/b8/archive/2012 ... iency.aspx
Oh yes. This is something on my "wish list" for a while, with the nearest available being in Windows Home Server. What is it? Finally, the native ability in Windows to assign arbitrary disks to a storage pool and let Windows transparently take care of data distribution and redundancy within.
For example, currently I use 2x2TB hard disks in my main system for storage, set as a software mirror for data redundancy. If I want to expand the existing mirror (not far off!), I'd have the headache of buying another pair of disks and managing data between them. With Storage Spaces, I can just get another single disk, and the pool would increase seamlessly with the files being dispersed as required to maintain the desired redundancy level. It supports mirror and parity modes so you can balance risk and storage costs.