I think this addition is extremely valuable, but courting node users is a weak argument for it. For me, it is more about the growing importance of semi-structured data, as well as other forms of data that are difficult to model outside of row-tuples and joins. Hstore was a hack...really useful, but a hack nonetheless. Hstore2 is a legitimate kv-store. Now if we could just do the same with a graph-store.