While we work on our full review of the Canon 5D Mark II, I wanted to share a quick tip with you all.  

One of the new factors we photographers, turned cinematographers, need to take into account now is audio. Audio done well can make a video, just as well as audio done badly can really harm you.  The Canon 5D Mark II has a small microphone built in just next to the 5D name plate on the front of the camera.  This microphone is actually pretty good for it's size and location, but it is limited by those factors as well.  Your audio levels will change while your hand is in front of the microphone making focus adjustments, or even just holding the camera steady (which is actually quick tough to do.)

Canon 5D Mark II with Rode VideoMic (The Foam Proboscis)

The easy solution is to take a page from all of the beginning video / cinematographers out there and use an external mic.  I pulled this Rode VideoMic out of my video kit and plopped it on the Canon 5D Mark II's hot shoe, connected the mini-phono cable to the mic jack on the side of the Canon, and away I went. The mini-phono jack and hot shoe mount originally made for Mini-DV camcorders makes it a perfect fit for grab and go video shooting on the Canon 5D Mark II. Not to mention the microphone condenser itself is suspended between a web of rubber shock mounts so the mic won't pick up your movements either.

The Rode VideoMic costs about $150 and will require a 9V battery (which will give you around 100 hours of run time.) Other than some larger Compact Flash cards, this would be my first buy on my track towards shooting professional videos on the Canon 5D Mark II.