It's sad Tomasi and Gleason won't be able to continue their story, but to be honest, this series hasn't really been good or consistent post-Superman Reborn. Bizarroverse was the best arc since Black Dawn; a lot of the issues between them were fill-ins from other writers and artists, and I can only recall liking the Sinestro/Parallax two-parter, and the James Robinson penned Suicide Planet.
I don't get why for the past eight months or more, the series was written/compiled by these kind of stand-in stories and content. Maybe Tomasi and Gleason ran out of steam. Maybe not, as I saw someone else speculate that editorial may have done it intentionally to give more limelight to Jurgen's Oz Effect story over in Action Comics, which was running in parallel.
Regardless, I'm going to miss this period of Superman, the township of Hamilton, its fare, the school, the farm, Kathy and Maya (hopefully we will keep seeing them in Supersons) and that evil alien cow that produces mind control juices (which is also now the receptacle of Manchester Black)