I was reading through the Firefox 2.0 forums and noticed that someone pointed to a bug report that referenced a new Firefox 2.0 preferences page. It is all done in ASCII art but you can get the gist of the new interface we might see in later builds.
I would say that I like what the new interface might look like. Everything is grouped together better and it looks like there will be less tabs to sift through to find the settings you are looking for, especially the Privacy settings. They have placed almost all of the Privacy settings onto one single page instead of having 6 different tabs.
Overall the changes look nice. According to the bug report they are going to try and get this implemented by Firefox 2.0 Beta 1, which is scheduled for release on July 6. This will probably be part of the visual refresh (new theme) that is supposed to be ready by Beta 1.