Eager to catch up with Marvel in the summer blockbuster dept., Warner Brothers and DC plan to screentest a bevy of young stars for Christopher (Memento) Nolan’s new Batman film. (Of these choices, I’d go with Christian Bale.) Also is comic casting news, it turns out cut-rate chanteuse/Newlywed Jessica Simpson will be playing the lead in Mort the Dead Teenager. Normally, this’d be a non-story, but she had been rumored to play Sue Storm (Invisible Girl) in the upcoming Fantastic Four flick, which — if true — would have instantly erased any interest I might have in the project. Now, Naomi Watts, on the other hand…