General Idea
This is essentially what my final design came from. The part on the right is something that would be implemented later if at all. It is a overflow drawer for tabs which would appear down the right side of your window. The plus under the tags on the left shows tags which didn't make the cut. Please see my snapshots for a better idea and more explanation.
with some notes
Boolean Sorting
Here are some other ideas I had for implementing boolean sorting before settling on smart-folders
Lose the Sidebar
Here is a drop down menu version of the sidebar. This will probably be an alternative view if you don't want to take up screen space.
Tag Web
This is a tabless visual representation of tags, which was another idea. The color of the connecting lines shows the tag that is shared. When you rollover an icon it would grow to show a decent preview of the page, it might even zoom to the area of the page your mouse hovered over most. This might be implemented later as an alternative view. (activated by F8?) This would give you an overall view.
