ExpressCache is a new, presently shipping, OEM product that we announced at the CES trade show last week.
ExpressCache is a software storage performance solution that requires both an HDD and an SSD (smaller affordables drives are all that is needed). In short, ExpressCache effectively combines the two drives, greatly increasing performance (typically by a factor of 2 or 3) by caching the frequently used data on the SSD!
You can read more about ExpressCache here.
There are plans to broaden the supported platforms and potentially expand the availability of the product beyond OEMs. The time frame for that is undecided, but it may be later this year. We'll certainly announce any such events on our website and on the blog, so stay tuned.