Those pesky gaming censors have done it again, potentially letting the cat out of the bag when it comes to a new version of Quake 4. A new amendment to the ESRB Website updates the game from simply being for "Windows PC" to now also include "Xbox 360" and - more excitingly - "PlayStation 3".
While it's not the sequel we're still clamouring for, seven years later, it's something that should introduce the title to a new audience, potentially as a downloadable title. And, if you look through those rose-tinted glasses, it's a precursor for news of a sequel!
...at this stage, nothing yet has been confirmed, so try to keep your hopes under control for now.