I wish I was able to contribute in some way to the elementary project... but I guess that my knowledge of C only isn't much helpful.
That panel looks too much like IE's favorites panel .... DO NOT WANT
Just planned to start working on eFirefox 4.0(gonna skip some versions) for firefox 4.0+ and this is already wonderfull inspiration ^^
but what about the tabs and the bookmarks bar? do they only show to the right of that panel? I think they should, like marlin. but will it still look good, specially the bookmark bar, with the handle between them?