About.com had een interview met screenwriter Mark Bomback, die momenteel bezig is met het schrijven voor Die Hard 4.

[eng]Is it really being called Die Hardest?
It's not going to be called Die Hardest, at least not to my knowledge. I think that it was in development at one point and it might have been called Die Hardest, but it was an entirely different plot. It was a whole different movie. It wouldn't make sense to call this one Die Hardest. Maybe they will, I don't know. There are worst titles in the world. I'll tell you this. On my script pages, it doesn't say Die Hardest.

Is there a different subtitle?
We just call it Die Hard 4.

What guidelines were you given?
I think the only big mandate was to make it feel like a Die Hard film.[/eng]

Lees het hele interview hier