When Apple offered the beta version of Safari 4.0 to the public, they introduced a new layout with the tabs replacing the title bar at the top of the window. In the final release of Safari version 4.0 did not include this new layout and I’m guessing the reason are the reaction from the users. But in this scenario, Apple reacted too fast; the interfaced was a definite improvement – it just needed a little tweaking.

The Beta Tab Layout: With the Safari Beta 4.0 Apple tried out Googles approach with the tab bar at the top of the window. The layout was however, removed from the final product.
To the best of my knowledge, Google Crome introduced this tab layout and Safari followed. The layout makes it perfectly clear that both the address field and page content is unique to each particular tab. Moving the focus to another tab affects the address field and the page content, which is exactly what the user expects. User expectations matching reality is a typical trait of a good user experience.
Placing reversed tabs underneath the address field connects the two, but the page content is left hanging – not visually attached to either of them.
The main complaint from users as far as I could tell, was that the handle used to move the tab was too small. Missing the handle caused the entire browser window to move which of course becomes annoying pretty fast. This frustration could easily be solved by adding optional functionality using the Option key. Hitting the Option-key should have caused a grab and drag anywhere on a tab to move the tab and not the window. Easy. This way the handles to move the tab could remain small as any user that often reorganizes the tabs, would be interested enough to find the alternative method (the shortcut could be part of the tool tip when hovering the handle). The remaining users would likely not mind hitting the small drag target as they are not likely to reorganize the tabs very often.
In my opinion I hope Apple gives the tab based title bar another chance. It is a good and intuitive way to organize the tabs that even saves precious screen real estate. Two good reasons to keep the design. At the very least, they could include it as a user preference.