One thing we have learned from KDE4 is that its not a good idea to make drastic change to a desktop environment that the users have been used to for a long time. Hopefully the Gnome developers will keep that in mind as they work on Gnome 3.0 release for next year. Gnome is known for making subtle incremental changes instead of doing major overhaul, but the changes they have planned for Gnome 3 is much bigger than we have come to expect from Gnome.