Iterations of the GNOME Shell Design
This write-up from the User Experience Hackfest contains initial ideas for the GNOME Shell that were discussed there. It also contains the initial mockups for the GNOME Shell that were drawn by Neil Patel. Vincent Untz's blog post has a summary of the ideas discussed at the hackfest.
Application Browsing Iterations
Overview Mockups With a Black Theme
Here are the mockups for the overview with a black theme from Jeremy Perry. They also include a mockup that displays the search results in the main dash area on the left.
GNOME Design document
Important milestone releases:
5 July 2009 (GUADEC)