Yeah, i know this question has been asked to death.
The reason I'm posting is because I made great strides getting it working, but I had some bad luck at the end. I documented my findings though, so I figured that I may as well share what I learned.
http://darthcircuit.wordpress.com/2012/07/05/hacking-a-seagate-hard-drive-to-work-in-the-xbox-360/Sorry if this is the wrong section. I hope to be able to finish this soon, but I am in a rut at the moment with this project.