The cards use a cheap FPGA instead of the typically built-in ASICS (which use the ioDrives, for example).
The price should be about $3.89 for each GB. This makes it an extremely affordable as an enterprise flash solution. There is also a downer, however. Unfortunately, the minimum order quantity for Fusion-io is still 100 pcs. So that only currently Apple, Facebook and Co. can benefit from the offer at the moment.
Update: 2013-02-21 We will get ioScale demo hardware from Fusion-io in early March and will be testing the card extensively. The results are published here.
Update: 2013-03-01 We now have the demo card here. It should be noted that the ioScale 3.2TB card comes as a full height version.
The full test you can read in our Fusion ioSclae test Artikel.