i would vouch for a "page-only" browser window with hover controls. like a video player
I use Pentadactyl, and a Shift-B (show buffers) followed by a <tab_number>gt will get me to wherever I need to go.
This is, of course, not discoverable, and therefore not really suitable for the demographic whose problems this article is hoping to solve, but for someone who's willing to put some time into learning a program (or who already uses vim), it's pretty spot-on. I, for one, love it.
I should add that the problems this article is trying to solve really ought to be solved through a thorough integration of the browser tab-system with the window manager. That, of course, necessitates a thorough rethinking of the window manager, also. But that was the problem tabs alleviated in the first place, right?
The WIMP model really is the walking dead.
engage beating a dead horse here
The lack of functionality in Chrome extensions is why I (and judging from the comments I've seen in most Chrome vs Firefox threads, many other HNers on Firefox) refuse to switch to Chrome despite its much touted speed. Until I can get Pentadactyl and TreeStyleTab, its just a downgrade in usefullness.
There's people arguing, of course, that that's really poor usability, because you can't see what you can do. I guess it's a matter of taste as much as anything, and it's probably more of a power-user thing.)
The vast majority of the time, I don't interact with the chrome of the window: the back and forward buttons, the address bar, tabs, etc, so why not get that out of my face while I'm not interested?