I think it proves that Carmelo sees Rondo as a good basketball player who could really help the Knicks out.
I also think that Rondo and 'Melo would play together pretty well, especially with him at PF. A Rondo/'Melo 1-4 pick and roll would be fun to watch.
New York doesn't have anything we want, though.
FWIW, I don't see Carmelo leaving NY.