I believe the DNS-1200 was released sometime earlier this year.
The Taiwan D-Link site (http://tsd.dlink.com.tw/) contains two DNS models not available in the U.S. (or anywhere that I know of). the DNS-346 and DNS-356. Both of these models have been out for some time (at least on the TW website).
The DNS-346 looks like a rebranded DNS-343 (i.e. ShareCenter). Looking through the posted manual, I don't see any discernable difference, neither externally nor internally.
The DNS-356 is a "5-Bay iSCSI Storage Enclosure". From the photo in the user manual, the DNS-356 looks like a garage project that never took off. It's not the prettiest looking box.