It's a curious thing that (over the years) so many people have attempted to bring the desktop window managing experience into a web browser. More and more I've found myself going the other way and wishing for less window management on the desktop.
Quick link to demo: <a href="http://devthought.com/wp-content/projects/chromekit/" rel="nofollow">http://devthought.com/wp-content/projects/chromekit/</a>
For a minute there I thought someone modified WebKit so the browser widgets that are normally drawn from a toolkit (GTK, Cocoa, etc.) such as scroll bars, buttons, text boxes, etc. were actually created with CSS/HTLM/Javascript.
This project should give Apple a slap in the face. Banning desktop-like apps will be impossible with this. I applaud you!
I agree that ChromeKit (or whatever you will be calling it) should be used with care as to not become bothersome. I wish you luck in your endeavors.