From imdb:
Cast overview, first billed only:
Bruce Willis .... John McClane
Jeremy Irons .... Simon Gruber
Samuel L. Jackson .... Zeus Carver
Graham Greene .... Joe Lambert
Colleen Camp .... Connie Kowalski
One suggestion..
Maybe Willis can get James Woods in the cast too.. I can see ultra smarty conservative James Woods ( MIT grad ) playing the role of a spy or high level general.