VMWare vFabric SQLFire vs memcached vs AppFabric vs ???

VMware vFabric SQLFire is an in-memory distributed SQL-based cache which can work with a traditional database to persist data to disk. Distributed, in-memory shared-nothing fault-tolerant SQL data management system. It offers a JDBC or ADO.NET interface for querying the datastore in a pure SQL manner, but the keys and indexes are stored in memory to provide high scalability, availability and better performance. Leverages the "time-tested", production GemFire technology but adds a SQL interface. SQLFire is being offered as part of vFabric Advanced for $1,800 per VM, but it will also be offered as a standalone product


http://communities.vmware.com/community/vmtn/appplatform/vfabric_sqlfire