I found an article by Paul Thurott confirming this information. I know that this isn't a whole lot more information than was originally posted but Paul is generally a reliable source of information.
He also said, cryptically, that Microsoft will be bringing the Xbox 360's remote media experiences, codenamed Pica, to various consumer electronics devices, like TVs, as well as PCs. This means, essentially, that the Vista-compatible Media Center Extender technology in the Xbox 360 will soon be available to a much wider range of users.
My bet is that the feature will be included in the next Media Center refresh. Let's just keep our fingers crossed.
John