property graph standardization recommendation

I am working to advise a government client on data architecture in the area of graph data technology.  Is there any work on-going to explore the property graph data model and potentially make a recommendation to W3C regarding standardization?  The only reference I was able to find is dated 30 September 2013.  I could not find any reference to work done since then.

Kim Halladay
MITRE
Office: 703 983-6312