Yesterday when I posted the MIME bar prototype, I was given some ideas to make the dialog easier to use and fit better into current UI designs. I was mostly thinking about the desktop flow, but UI ideas are always welcomed. I whipped up a new version in Glade and connected the signals to the existing code and it's already working. It's not something that I could release because it's hard coded for our software packages, but might be a good idea for a GNOME project in the future. I guess in theory some more X-Categories could be added so it knows where to place these items. I'll be creating similar ones now for word processing files and for Pictures.
Shot below, I like that it has a similar appearance to the main-menu.
Update: A quick dupe of the screen and change of the thumbnails and the Picture and Audio/Video dialogs are starting to work. Thanks again Kevin for the awesome 'nailer' program for the videos.