I think the perfect guy to write it is DC Comics's biggest star writer, Geoff Johns.
Being a talented comic writer =/= being a talented film screenwriter.
As I pointed out, Johns was Donner's assistant. He also wrote for the Blade TV series and he'll be introducing The Legion of Superheroes to Smallville.
I'm sure a man of his talent can write a screenplay. Look at the crap that gets produced these days and convince me otherwise.