Monday Morning Conversation: Web 2.0 Storage

I received an email the other day with a press release from a company that is offering a pretty slick product/service.  The company is called Nirvanix and they offer storage to web companies via a standards based API (SOAP or REST interfaces).  It all sounds pretty cool to me. 

What are you guys seeing out there in this space?  What are these companies using as the backend hardware and software to get this done?