I got the impression that Del Toro - who probably would have made a good stab of it - simply wasn't willing to wait around any longer to get the movie finally greenlit. Which it presently isn't due to the MGM financial mess at present.
It's a shame. But he has a lot of other projects he wants to do and I don't suppose he can sit and wait forever.
'If the Apocalypse starts, beep me!' - Buffy Summers
'The sky's the limit.....' Jean-Luc Picard, 'All Good Things'
courtesy of Saquist