From Discovery and Gaiam's official press release:
Into the Universe with Stephen Hawking -
"In an epic, new kind of cosmology series, [Into the Universe With Stephen Hawking] gives us the ultimate guide to the universe. From the nature of the universe itself, to the chances of alien life and the real possibility of time travel, watch the world's most famous scientific mind at work through the limitless possibilities of computer animation."
Sunrise Earth: Alaska -
"Awaken to some of the world's most spectacular pre-dawn sights and sounds with Sunrise Earth: Alaska. From the quiet beaches of Lake Homer to the breathtaking glaciers of Kenai Fjords, watch as the enchanting residents of Alaska come to life when the sun comes up."
Into the Universe With Stephen Hawking runs 180 minutes on Blu-ray while Sunrise Earth: Alaska runs 200 minutes.
Further technical and supplementary details are still unknown.
Into the Universe with Stephen Hawking streets on January 31st, while Sunrise Earth: Alaska is expected to street on January 17th.