At today's Apple event, a new hard drive option was mentioned by Apple's Philip Schiller (Senior VP, Worldwide Marketing) when discussing the latest version of the iMac. The Fusion Drive was described as a small solid state device "fused" with a larger traditional drive - which is cool, but not revolutionary. Except that this may not be a "traditional" hybrid drive, but more akin to something borrowed from the Enterprise - auto-tiering.
Time will tell....Fusion Drive sounds similar. In a caching solution, like Intel's, files live on the hard disk drive and are temporarily mirrored to the SSD cache as needed. In an enterprise auto-tiering situation, and with Fusion Drive, the data is actually moved from one tier to another, rather than only being temporarily cached there.