You can't cite a source more informative than Microsoft itself, and XBox.IGN did just that. Here's a blurb:

A recent news story on the MSN Computing Central section has caused a small controversy around the web due to a statement made in an editorial entitled 2000 and BEYOND: The Future of Gaming that makes reference to the Xbox as now officially known as the Raven. Being the paranoia hounds that we are here at the IGN towers, we immediately called a spokesman for the company, who responded that there is definitely no truth to the Xbox being called Raven. Whether the mix-up is due to previous plans to use Raven as a console name is unclear, but whether or not the bird would have become the mantle for Microsoft's console is old news. Xbox is here to stay.

Well, if that statement was there earlier, it certainly isn't now. Microsoft may have edited the article in the intervening time. Thanks go to 3of9 for informing us about this one! And the rumors grow thicker...