I got it here:
http://mdxonline.dyndns.org/archives/2007/..._ver16_dl.shtml
It's not the beta release and on the release notes it says this was released on 1/19/07 (today).
I'm gonna buy another Series X, but can't decide if I should wait till the Xbox June event (maybe they get discounted) or just buy now. What do you guys think?