I found a trailer for the new Halo Legends anime movie that is in the works over at Trailerspy.com.  From what i can tell, it looks hand drawn, mixed with a little 3d cell shaded.  Looks interesting!  The trailer does not reveal too much though, just some screenshots.

You can view the whole trailer here on the site or below on my site!

Quote from the Wiki

Microsoft announced at Comic-Con 2009 that it was overseeing production of a series of seven short anime films, together called Halo Legends. Financed by 343 Industries, the animation was created by five Japanese production houses: Bones, Casio Entertainment, Production I.G., Studio 4°C, and Toei Animation. Shinji Aramaki, creator and director of Appleseed and Appleseed Ex Machina, serves as the project's creative director. Warner Bros. will distribute Legends on DVD and Blu-ray in early 2010, Six of the stories are officially part of the Halo canon, with the seventh, made by Toei, is intended to be a parody of the universe.