Add basic support single volume deduplication to NSS at the command line with OES. Add it as a reporting option enterprise wide across volumes in File Reporter. Make it an configurable administrative task in Storage Manager complete with rules to monitor and automatically enforce deduplication policy across all enterprise NSS volumes.
I don't see a filesystem needs certification or support if the data being de-duplicated is OS/filesystem independent - ie block level(the only currently serious de-dup method). You don't need to ask for an NSS certification in hard disk, SSD or even possibly a SAN.
But, de-duplication is generally available on the storage arrays. If this were valuable to us, we'd already have a de-dup array. We did some tests with tegile and purestorage arrays and had a 1.7:1 de-dup/compression ratio on our nss filesystem and decided de-dup wasn't a high requirement for us.