Wow, surprising news coming out of Build in Anaheim... looks like Windows Server 8 will include a technoclogy Microsoft is calling "Storage Places", it's being described as this:
Source: http://www.mswhs.com/2011/09/drive-pooling-returns-to-windows-server-8/
Even if they don't implement this in a future version of WHS, I wouldn't mind installing Windows Server 8 and rolling my own backup solution.
A new Windows Server 8 capability highlighted on Wednesday is 'storage spaces', which will let users take just-a-bunch-of-disks (JBOD) collections and carve out a space or pool that shows up as drive using the new Server Manager. Users can use this feature to simply attach JBODs to Windows Server 8, explained Brian Surace, a senior program manager on the Windows team. No external storage array was used to create the pool. The improved Server Message Block 2.1 (SMB 2.1) protocol was used to help make this pooled storage available, he said.
Source: http://www.mswhs.com/2011/09/drive-pooling-returns-to-windows-server-8/
Even if they don't implement this in a future version of WHS, I wouldn't mind installing Windows Server 8 and rolling my own backup solution.