I have some good news and I have some bad news for you guys.
You all seem to like Die Hard 2 the least, so according to IMDB.com the writer for Die Hard 2, Doug Richardson, is also writing Die Hard 4.
Now the good news, the writer of Die Hard 1 and Die Hard 3, Roderick Thorp, is in charge of the characters and casting for Die Hard 4.
I can't wait to see who Willis acts with in Die Hard 4 after Samuel L did such a great job in Die Hard 3. My guess is that it will be a female role.