Hey StevenEsqTwo I for one send a bucket of appreciation for posting this initial discussion and after discovering the Perian solution on a different forum (http://blog.lib.umn.edu/mcfa0086/discretecosine/164630.html) which only solved the read part of the XDCAM issue, you're post drive me to my Mac Pro with a clean install of Snow Leopard and FCP 7.0.1. I copied these codec files to the folder as suggested by your good self and it worked. I was so stuck by this upgrade (Apple Codec pack 1.0.3) in a work/professional capicily I thought that many others would also benefit from having a fresh codec pack (pre-1.0.3) to download as opposed to a fresh install of FCP/Sony Transfer program. I know this wasn't an option for my MacBook Pro.
Anyhow, any love and thanks that's aimed towards me, feel free to take a chunk of it SteveEsqTwo and keep up the helpful posts, it really saved my edit at the time, which was a 300GB/8-HD-multi-cam 94-minute concert, that I still made the deadline on. I will also be happy to continue active posts with guards anything Apple related, especially for the pro-users.
Cheers,
MAK