Writer Justin Jordan, who took over the book with Superboy #20 just a couple months ago, has apparently already decided to walk away from the Boy of Steel.
According to Bleeding Cool (the site that was first to report about Andy Diggle and Joshua Hale Fialkov leaving their DC books), Jordan has walked off the book due to creative and editorial differences. The writer previously tackled the late Team 7 and Deathstroke, and has recently taken over Green Lantern: New Guardians. Luckily, Bleeding Cool reports that he has not left New Guardians. It is unknown when Jordan’s last Superboy issue will be published.
Source: Bleeding Cool