There are motherboards that are about the size of a CDROM drive in footprint, weather or not they will work with NL is up in the air and anybodies guess.
As to the case that is able to not only hold 10 drives and the mini-ITX form factor MB, I don't recall ever seeing that. If you want to get allot of drives in a small footprint you may end up going down the route of SAN storage hardware. There are solutions out there that take either SAS or SATA drives and some even have hardware RAID controllers built in and present the drives as one large volume or volumes via the interface which may be SAS/SATA, SCSI, FC-AL, or even iSCSI. The down side is that they are generally not cheap on the front of it.
To get you started you can look here:
http://www.mini-box.com/site/index.html Their prices are out of line but they show a good depth of product and will help you with the basics of the hardware needed to fit yourself a compact NAS solution. As to a case, that is likely going to be some sort of custom fabrication.
Mike