I couldn't find anything posted on this yet so here goes:
http://www.bit-tech.net/news/hardware/2010/02/03/silverstone-announces-hybrid-ssd-hard-disk/1
SilverStone has just announced its HDDBoost, a device that teams an SSD with a hard disk. The aim is to offer the incredibly fast data access speeds typical of SSDs with the high capacity of a hard disk but to make it easy to use, so both appear as a single storage device in Windows. Essentially, the HDDBoost uses an SSD as an huge cache for your hard disk, theoretically delivering the best of both technologies with no compromise. This sounds almost as magical as the Lucid Hydra, but with a much better chance of success.
http://www.bit-tech.net/news/hardware/2010/02/03/silverstone-announces-hybrid-ssd-hard-disk/1