Just a drawing tool in the browser. This doesn't do anything different than Photoshop or Omnigraffle, if the web designer is smart enough to reuse layers / components. It could be a really useful though if it had support for more than absolute-positioned, fixed-sized elements, and used the browser's layout engine instead. Today's biggest problem is that web designers use Photoshop for coming up with mockups and then…
The hard part about using the browser's layout engine is that it is limiting to the designer. We'd have to snap things into say, floating position, etc. And we'd have to know exactly what the designer was thinking when they're dragging some element around. Or they would have to know about floats, and how to use them. We think (right now) that the best way around this is some kind of constraint system, like CAD apps h…
As a user, I want the designers to be limited. Scaling by percentages and using constraints sounds like an improvement. On the other hand, I like your minimalistic tools.