The MKE400 is a great Mini-Shotgun, cardioid mic. I think I first found this guy when I was trying to figure out what Kevin Sites was using during his stent as a War So-Jo (Solo Journalist) for Yahoo.com. I have yet to determine if this was what he was using, but it doesn't matter because the MKE400 rocks.
I'm going to post a full review on the MKE400 as well as a full write up on audio recording functionality of the 5D. But for now, let me show you how big of a difference a good, narrow pattern mic like the MKE400 makes when shooting on the 5D Mark II.