About To-Love-Ru, the artist for this series wrote Black Cat, which went pretty long, and before that he had a series that died after 3 volumes.
I really like Double Arts, honestly, I like most Jump series, ecchi romances do tend to be pretty lame, I eventually grew to hate Ichigo 100%.
Nurarihyon no Mago, Psyren, and Double Arts all carry the constant threat of series death at this point. I wouldn't mind if Toriko and Bari Haken died so that they could live on.
Thankfully Boku no Watashi no Yusha Gaku died at chapter 66 two weeks ago, and Samurai Usagi died at 67 two weeks before that.
Maybe that will give them a bit of breathing room.
Pic is the table of contents from two weeks ago. I'm not entirely sure how much series placement is related to popularity, but generally the farther down the worse off.
This thread has several ToCs on it: http://mangahelpers.com/forums/showthread.php?t=22065