In the Kirby copyright thread from a few months ago, it came out that the Kirbys were seeking not only the rights to Spider-Man, but all the supporting characters who appeared in the comic up until issue #6 (I see that the current complaint pushes it up to #7).

As I stated then (to the annoyance of some), claiming the fruits of those Ditko drawn stories as being Kirby creations struck me as being a rather unsavory move.

I'm guessing it is a move aimed at potentially getting more money from the profits made by the films than they could get by just claiming Spider-Man alone. Film series characters JJJ first appeared in #1, Doc Ock in #3, the Sandman in #4, and Curtis Connors in #6.