I worked through these fedoraproject.org redesign header mockups today with Sijis’ feedback. I’m really liking the last one, #7. :) Sometimes you just have to keep trying, keep experimenting, until you discover something that works.
The problem we were trying to solve here was having two competing navigation bars, and placing the navbar in such a manner that I felt it wouldn’t necessitate an awkward non-front page layout. In #6 and #7 you can see the two navbars have been collapsed into one, and it’s above the main banner / slideshow area. Sijis suggested moving it above the banner and I think it works really well. The problem with it on the bottom is that if you have a subpage that doesn’t have a banner, it makes the nav bar move up and down the page making it much more complicated to move between pages via that navbar (when the navbar itself jumps around the page you have to refind your place on the page to click on a nav item.)
Anyway, I hope these are at least nice eye candy, if not a more interesting study of how to solve a design problem through iteration. :)