As much as I love JJ2, just face the fact:

Epic Games has the highly succussful Unreal Engine, and the Second Generation Unreal Engine. It can make MILLIONS with them....

Why would they spend there time making JJ3 which although has a nice community, it has no where near enough players to shift enough copys of the game from shops, therefore would most likely make a loss.

Epic have become sucussful company and a leader in FPS engines, they dont care about small time things like Jazz Jackrabbit.

We just gotta face that, and be happy with Jazz 2!