Windows 2008 R2 Clusterd File server using VHD's

I wanted to run this by the community before I implemented it.  I'm thinking of cutting up my file server into smaller chunks using VHD's.  Please note I am not planning on using them as Virtual Machines rather straight mounted drives.

Instead of one giant 2 terabyte drive I want to do the following:

1)  Create 1 giant 2 terabyte drive (read the rest please)

2)  Create VHD for each department of the organization

3)  Mount those vhd's on the clusterd file server (Windows 2008 R2)

4)  Use DFS to provide a single unified namespace

5)  Backup / Restore based on the mounted VHD's rather than the one large drive

This should provide me with some flexability, but I'm not sure about the performance ramifacations.

Your thoughts?