This could be an interesting 'battle', and that's how they (or Shuttleworth, at least) is framing it. Ubuntu is easily one of the most popular distros for Desktop users, so it holds a lot of sway. If ChromeOS/Chromebooks explode, that will help expand the "upstart-using" market. However, Lennart makes some good points about an outdated software stack, and history shows Ubuntu's not real good at maintaining core software/giving back to the community. They're better at taking what's out there and putting little niceties on top for user interaction (although with Unity...).
I would be interested in seeing how "rolling distributions" such as ArchLinux are going to deal with this...
Either way, it's something cool to keep an eye on.
It would be a good topic for a talk at LUV-main if you're interested Eric :) All the best, Lev