StorSimple's application plug-ins allow their appliances to be more intelligent about data placement. The SharePoint plug-in not only puts the database on the appliance's internal flash storage and unpopular content off in the cloud, but also takes a page from Google's PageRank and keeps content that is linked to multiple SharePoint pages locally on flash or SAS disk.
The Exchange plug-in actually makes Exchange 2010's built-in archive feature usable by determining the difference between a user's primary and archive data and storing the archive data in the cloud.
StorSimple has three appliance models, from the $15,000 flash-only 1010 (supporting up to 10TB of data) to the $50,000 7010 (which can support up to 200TB of data and fault-tolerant pairs of appliances). In addition to deduping the appliances, perform AES-256 encryption on your data to keep it safe from prying eyes.