So the Red Skull will be no one else but...
Joe Quesada himself!
... well that is according to Brian Michael Bendis' Tweet:
Breaking news: @JoeQuesada cast as Red skull. with highlights :)
This guys are really having a good time aren't they... How I wish I could be part of those meetings and read that awesome cap script... so that I'll have real news to give you guys...
-access out. Godspeed!