I think it is excellent news. We already have a variety of GUI based browser (epiphany for gnome and konquerer for KDE). Chromium (the Chrome based browser for Linux) is a long way off from being production ready though (it still doesn't support plugins like flash or gears).
ComputerWorld has an article today[1] about the privacy aspect of ChromeOS. As it's open source, any one that wants to know what the code is doing can do so. That's something that Microsoft don't offer.
� -- simon
[1]
http://computerworld.co.nz/news.nsf/tech/00B8BB6CF3BAACF0CC2575ED006F3D16