I saw this overview of the 5d Mark II on Canon's Professional Network site today. It's a great resource to understand the major improvements in the Canon 5 line.

My personal view is that the camera simply rocks!

Canon Professional Network - EOS 5D Mark II Masterclass:

EOS 5D Mark II Masterclass 15:38 David Newton examines the key features of this groundbreaking camera that shoots stills and full HD video.

EOS 5D Mark II – David Newton, CPN’s Technical Editor, explains the major features and technologies in this 21.1 megapixel full frame SLR.

Here's the link to the page: EOS 5D Mark II Masterclass