While double-, triple-, or, in the case of the Evil Dead franchise, quadruple-dips are quite commonplace amongst film titles on DVD, they're still relatively rare for television shows outside of packaging updates (though I suspect we'll see that change soon as existing series are issued on Blu-Ray with new features). Fox leads the charge by revisiting 24: Season One as a new Special Edition. And it makes sense. 24 hadn't yet become the phenomenon that it is when they issued the first version of Season One, and it's consequently lacking on special features, whereas later seasons were packed with 'em. So it only makes sense to redo the first season.
According to a Fox press release, the new extras include an all-new documentary called "The Genesis of 24," five extended episodes (comprising the hours of 7PM to 12AM, or the final five episodes of the season), twenty-five extended or deleted scenes, yet another, never-before-seen alternate ending for the season finale (the alternate ending seen on the original DVD will still be included, as well), commentaries on the premiere and finale, and two "The Rookie" online short films. Whew! I think all that should at least make this encore worthwhile to hardcore fans. The original introduction from Kiefer Sutherland will also be retained from the first release.
The new version will be readily identifiable on store shelves by its metal tin packaging (complete with ticking digital counter... but only four digits' worth) and will also include "special introductory letters from both series co-creators on their inspiration and challenges working on this groundbreaking show."