Note to interested developers... there is a HUGE market for a disruptive tool in this space. If anyone is interested in working on such a tool, I'm game.
This is a constant frustration for web designers. Photoshop allows you to create fantastic visual effects, but the layout tools are abysmal. Fireworks is well... Fireworks – Adobe's "redheaded stepchild" in the tool chain. It's buggy with a slow, horrible UI. While some of Fireworks tools solve some of the layout problems (nine slice scaling, better vectors, grouping), their lack of decent masking and the horrible color picker and WTF interface actually slows designers down to where it become a draw.