I used the splitter bar heavily in my last application, and while it offered a huge improvement over static HTML the layout was fixed - albeit resizable.
I think an incredible improvement in UI capabilities would be to allow a user to customize the precise layout of each components much like Eclipse/NetBeans allow advanced users a totally customized editing experience.
Is this possible with the new 4.0 layout model? I just watched a brief slideshow and it seems the idea is at least in progress by the extJS team.
Whats the word?