In his blog, Joe introduced the idea of a comic series for the unmade “Extinction” movie and, if those take off, comics of unmade season 6 episodes.
These would be Wraith-related because “Extinction” would have 2 Todds (“our” reality Todd and a future Todd) and the later seasons were slated to have Michael reappear.
Gateworld’s page about the movie plot: https://www.gateworld.net/movies/05.shtml
***As of 1/1/2014 this is all tentative. Joe expressed willingness to work with comic book creators and encouraged fans to write to MGM to express desire for these comics and spread the word.***