Conceptronic kindly sent me a CH3SNAS for my Debian porting efforts. The Conceptronic CH3SNAS is reported to be basically the same hardware as the D-Link DNS-323 but it costs slightly less. There were some reports that the CH3SNAS uses a 88F5182 chip whereas the D-Link DNS-323 uses a 88F5181 but nobody was able to confirm this for sure. As it turns out, there are two revisions of the DNS-323. Revision A1 uses a 88F5181 chip along with a separate SATA chip. Revision B1 on the other hand uses a 88F5182 which integrates SATA into the SoC itself. The CH3SNAS is equivalent to a D-Link DNS-323 revision B1. In fact, the mainboard of the CH3SNAS even says DNS-323 rev B1.
The Linux kernel from mainline only works on the DNS-323 revision A1 at the moment. Adding support for revision B1 should be trivial since you basically just need to initialize the SATA chip on the SoC and possibly adapt some other values. Unfortunately, the DNS-323 uses a very small serial connector so none of my serial cables work. If I can find someone who will make a serial cable for me, I'll fix up the kernel.