You just lost your artist to a competing publisher. The writer was overworked and chose this book to drop. You move a writing duo on to the book that has mostly been writing Vertigo stuff and one of the group had their previous super-hero book cancelled for low sales.
Then, before you can get any real sales feedback from the consumers (via retailers adjusting their orders over a few months), you create a spin-off title with the least heralded of the two writers (he of the cancelled super-hero book).
It takes HUGE BALLS to try to bleed the fans left on that book by trusting that enough of them will stick around on the original and buy the new title. I didn't know they allowed wheelbarrows in DC editorial.