An HD remake of Halo: Combat Evolved has been rumoured for quite a while, but Joystiq claim they've now got some more concrete evidence that an HD remake of Halo is indeed in development. Not only that, but they also state it will be releasing at the end of this year.
According to their source, the game is being developed by Saber Interactive, who're currently working on Inversion, and it will be developed from the ground-up; it won't just be an HD port. It will have a 1080p resolution and will support 3D technology.
Joystiq state that the game will be released on the 15th of November, 2011, as part of the 10th anniversary of Halo.