Today, on the eve of gamescom, Xbox and The Coalition are excited to announce that all fans who purchase Gears of War: Ultimate Edition, or the Xbox One Gears of War: Ultimate Edition Bundle, will be able to unlock the entire Gears collection via Xbox One Backward Compatibility. By playing Gears of War: Ultimate Edition on Xbox Live from Aug. 25 through Dec. 31, 2015, you’ll get access to Gears of War, Gears of War 2, Gears of War 3 and Gears of War: Judgment in Backward Compatibility when it launches this fall. In Gears of War: Ultimate Edition, you’ll get the complete remastering of the original game – painstakingly reimagined from the ground up with stunning next-gen graphics, recaptured and rebuilt cinematics, and modernized gameplay for an even better experience.
So, it's a questions of "buy one get 4 free". This is great news for Gears fans such as myself. I've already got GoW 1 and 3, never played 2 or Judgement, so I'm really looking forward to picking up the remaster and playing it.

Also, for those in the Preview Program, the games will apparently be already available to download and play, and you won't have to wait until later when backwards compatibility launches, but this is unconfirmed.