I hadn’t realized that “dogfooding” was now a verb (though Wikipedia concurs), but the usage in the Office 2010 Engineering blog just seems wrong. “For those of you who are dogfooding the Technical Preview build, thanks for all of the great feedback you’ve sent us.” But, the phrase is actually “Eating one's own dog food!” It does not mean beta testing! The author of the blog may be dogfooding, but those in the blog’s audience presumably do not work in the Office 2010 group. I imagine they are actually users of the Technical Preview. They are not eating their own dogfood. They are eating the blog author’s dogfood. This may or may not need a colorful term, but it would need to be a different term.
When I use Opal, I am eating my own dogfood (because I’m the developer). But the people who help me test prerelease versions are not.