And Firefox continues the inexorable march towards Chromeness by removing the actual title of the page from the window chrome. Don't get me wrong, I prefer Firefox. This just strikes me as wrong; the rest of the new UI is fine.
Is a title bar really necessary, though? The vast majority of the time, the exact same sentence is repeated again in the page as a h1. More prominently. With better styling. When I have the browser open, the favicon and the few characters on the tab are usually enough to figure out what the page is, and when it's minimized, the text shows up in the taskbar and alt+tab... I'm curious, what's missing?
I'd actually rather there was a simple meta key in each application, that you could use to just show you the vital data about a page. Meta data in webpages can be human readable - title, author, summary etc. How about an overlay? And how about have this for every app? Looking at an image - activate meta key, to see copyright info etc, listening to a tune, activate meta key to see tag info etc. Far better than hiding it under some menu item and distant properties tab.
Opera has an info bar, but it's not that user friendly.
That doesn't particulary address whether the title is necessary, it's great for window management, using windows instead of tabs. But you'll need a good window manager. I'd rather windows than tabs - though I fear that Opera introduced tabs as they were cheap windows more than anything else.