Thanks, I noticed. It's bit bold on the Mac at present for being an alternative to the Segoe family.
I wish I had a few Linux distros lying around to see what's happening there or knew of what typefaces are included by default on Linux + Mac OSX that would be a closer fit.
Please forgive my ignorance, but doesn't @font-face in CSS3 allow you to embed the font of choice and transmit it with the rest of the page? Wouldn't you, as Microsoft, be allowed to transmit the desired Segoe fonts to the user's browser for use on the site?