As announced yesterday, Tony Daniel is taking over as Writer and Artist for the remainder of the current arc on Action Comics which ends with issue # 21 (June). At that time he will take on assisting with a new "massive" project for DC.
In response to yesterday's announcement about Diggle leaving the title, Daniel posted on his Facebook page:
“Yes, many have heard, Andy Diggle left Action Comics after the first issue. I can only say I feel bad he made that decision. I think it was the wrong one, but that was his choice to make” .“For the remainder of the arc I'll be working off his plots to finish out this first arc ... so essentially, I become 'scripter' in the credits w/ Andy as 'plotter'."