While Dragon Ball creator Akira Toriyama's Jaco the Galactic Patrolman didn't seem terribly well received in Japan, the legend's new comedy was also always intended to be only a volume long. North American manga publisher Viz has finished the run in its digital Weekly Shonen Jump, so it's now time to find a replacement.
#SJNewSeries HINT: It's written and drawn by a creative team (not one person)! Stay tuned for more hints during the week!— Shonen Jump (@shonenjump) October 1, 2013
The leading, and probably correct guess is Takaya Kagami and Yamato Yamamoto's "Owari no Seraph (Seraph of the End)"
Baka Updates desribes the series, which runs in Blue Exorcist home Jump Square rather than Shonen Jump proper:
One day, a mysterious virus appeared on Earth which killed every infected human over the age of 13. At the same time, vampires emerged from the world's dark recesses and enslaved mankind. Enter Hyakuya Yuuichirou, a young boy, who along with the rest of the children from his orphanage, are treated as livestock by the vampires. Even in captivity, Yuuichirou dreams big. He dreams of killing vampires. He dreams of killing them all.