Google Enables Additional Storage Purchase For Google Apps
This means that Google Docs, Picasa Web Albums, and photos from Blogger can be stored on the newly available disc space, with users that upload lots of files to Google Docs, sync their Office documents to the cloud using Google Cloud Connect for Microsoft Office, or store and share pictures using Picasa or Blogger could take advantage. Pricing for the new data storage is the same as for Personal accounts, with an extra 20GB per year running you $5/year and an extra 16TB running $4096 per year.
The User Managed Storage service is enabled or disabled by the domain administrator, and the end user purchases additional storage using his or her Google Checkout account. Additional storage added using User Managed Storage cannot be pooled or transferred to another Google Apps user account and cannot be used for Gmail. Data stored using User Managed Storage is subject to the same ownership policy as other data in the Google Apps account. Honestly, the chance of Google losing your data is far less than the chance your single RAID drive will melt, so that's just a little food for thought.