User Observation Data for GNOME Shell
Take some time, grab a friend, and watch them interact with their desktop - Windows, GNOME, KDE, or OS X, whatever is their desktop of choice. Sit down and work out some common tasks that they need to do on the computer and watch them task-by-task interact with the desktop, or just watch them freeform interact with the desktop and ask them to narrate as they go along (this is sometimes referred to as a think aloud protocol study.) Take lots of notes, and post them here with some details about your friend's monitor, resolution, and experience/background with computers.
A sample set of questions for gathering user data, as well as the data about the default panel and workspaces set up of different distributions is here. The answers for these questions can be determined during the observation or you can ask these questions explicitly once you are done performing the observation.
Some general problems with the desktop are summarized here here.
It would also be good to create a set of personas for use in developing the GNOME Shell.