If you’re really mourning the impending loss of Windows Home Server’s Drive Extender technology, there may be hope.
Australian company Division-M is developing Drive Bender, which is described as "state of the art storage pool technology for Microsoft Windows".
Drive Bender is in beta (now closed) and is said to work on any version of Windows from XP on up.
If you’re happy to be a guinea pig and have your data backed up, you can keep hitting the site, or monitor the @drivebender Twitter feed for signs of a re-opened beta.