I like the activities view, and the search bar specifically, it's visually pleasing and robust at the same time. You can get to any folder or any application and launch it without taking your hands of the keyboard, just like Gnome-Do. However, I'd like to see some sort of plugin system implemented for issuing commands from the search bar.
For example, in Gnome-Do, with the Skype plugin-in you can call anyone simply by typing their name in search. Similarly, I believe you can run terminal commands from Gnome-Do. I'd like to see the same thing in the activities search bar through plug-ins. This means that users who don't want to be bothered by an overly complicated search-bar don't have to install the plugins but it still gives the option for those of us who like to use the keyboard only, with the fewest number of keystrokes as possible to launch and issue commands to any application.
Will Gnome 3.0 expand their search bar to include plugins?