I would like to take a moment to share my unRAID server with the group, and how to accomplish building one for yourselves.  Since WHS removed the drive extender option this is a NAS that acts in the same way.  Just use it as a mapped drive on your network to hold your files. 
The first link tells about the research put into the project and purchasing the equipment. 
The second link shows a detailed approach to the build with how I dremelled the case, routed all the cables, and installed the software. 
The third link shows a detailed approach to how I setup using Active Directory.
The fourth link will show using the server on a daily basis information.
I hope that this post helps users doing their research to be able to build there own server.
The Research and Specifications are here:
unRAID NAS Server Research & Specifications
The Build Process is here:
unRaid NAS Server Build
The Setup is here:
unRaid NAS Server Setup
The Use is here:
(coming soon)