Microsoft's previous efforts in creative software have been, well, lukewarm.
XP had Movie Maker and Photostory (the latter a free download from Microsoft's web site), which both allow you to take personal media and do a reasonable amount of editing and authoring.
But when it came to outputting your project, Microsoft only really gave you one choice. Windows Media Video.
People inevitably ask, "so can my friends play this on their DVD player?", and as a guy who supports Windows, I have to explain that these apps don't actually have the capacity to author DVDs. The response is always a disappointed "Oh...".
News source: APC Magazine