If it gives Diana two books, at least for a while, I guess we can't complain too much. I doubt Gail wants to leave yet, anyway, so you'll at least have that to counterbalance what you don't like.
Or it could just mean that DC's kicking Gail off the book. Morrison is known as a big fan favorite and Wonder Woman hasn't been doing too great lately. (The numbers went under 30,000 for the first time in a while.)
And now I'm going to have nightmares about that scenario. *shivers* I hate it when I scare myself.