I'm planning to write a enhancement request to Novell but I'm interested to hear what the community thinks about enhancing NSS.
For me the key enhancements to the file system would be
1) File system level de-duplication making for smaller storage requirements, smaller backups, smaller VM guests etc.... Something along the lines of SDFS (Opendedup)

2) File system level versioning of documents. A policy controlled versioning system that keeps each file commit as an incremental store. Versioning is becoming a common expectation these days due to things like DropBox, S3 bucket level file versioning etc...

3) Volume level snapshot. File level snapshot's are great but there are times when you need to snapshot an entire volume in one state

4) Symbolic links (hard and soft). While they are some what of a nice to have the power of symlinks are huge

Having used NetWare and Linux for many years I love NSS as a user file system but its starting to fall behind.
Anyway I'm keen to hear if others have ideas about other features that should be included