Seems since the SFF is not a hugely popular device from an accessories manufacture's POV, the pickings are currently slim for case in terms of hard shell cases and decent silicone or TPU. The only one that I can see from a decent manufacturer is one by Incipio for $20 but I found it on Amazon, not on Incipio's own site. I cannot stand cheap grade silicone and the TPU cases currently available are for colors I do not like.
Also if you check out the Incipio one, get from Amazon, not the AT&T store as they want $45 for it. YIKES!
EDIT--Also forgot Amazon has a Casemate Barley There case for $25