Kroll, In that case I like your mockup (however I think the top bar could use to be smaller, no more than 50 pixles)

Also, I had another idea for improving the diablo UI. Make an applet (either home, task, or statusbar) that would open a panel or window that would show all of the applications installed on the tablet. Basically it would show everything from /usr/share/applications/hildon on one scrolling screen, like maemo 5. However it would order the applications by frequency of use. The idea would be that each time a user clicks on an application in the menu it would keep a note that that application was used one more time. so it would sort them by the number of times used. Applications never used (like "help") would appear at the end while ones you used more often at the beginning. (I'm not sure if the maemo 5 menu does the ordering, iv never used it)

If there is interest I would like to develop this application. I am a long time maemo user but I have never developed for it. I am a php developer but I am learning python. If there is any interest and anybody would like to help me please let me know!