Headline: Read all about it. Open Source to Combat Longhorn.
Mozilla and Gnome have gotten together to look at how they can combat Microsoft Longhorn's strategy of merging the web and desktop experience.What "Open Source" should do instead of combat vaporware is to continue its multi-pronged, evolutionary, march toward providing a solid and secure platform upon which a multitude of innovative ideas can germinate and flourish. The aim should not be "combating Longhorn".
Just focus on providing incremental value to end users and developers of all stripes.