While the definition of SaaS is still "cloudy" Oracle has put its firm stake on the ground via the Exalogic box. This is meant to be the framework for private cloud that can run Weblogic and power the applications like JD Edwards, Preoplesoft, Oracle EBS and Siebel. I think more so it is for the foundation of Fusion Middleware for Fusion Applications.
Read more at the home page of Exalogic:
http://www.oracle.com/us/products/middleware/exalogic/index.html
