The tabs on top was a stupid idea, thank goodness it's gone.
I like how everyone who misses the tabs is stating their reasons for it, everyone who doesn't is saying things like "It's stupid. Why? Because it's stupid." Aristotle would be proud...
And I agree that it should just be a preference, that way those who don't want it don't have to have it; removing it entirely was unquestionably ridiculous.
What I don't see any reason for is removing the tab swapping feature in the beta (by grabbing the corner of a tab, you could pull it into its own new window or another open window as a tab). You can still pull a tab out into its own window in the final, but you can't seem to return it or add it to another open window as far as I can tell.
Send a bug report with that suggestion if you want to see those back. I did.
And in regards to the post on page 1, the reason it seemed like there were more beta testers that wanted the tabs changed back is that people generally don't report on features they like, but they do report on ones they don't, the assumption being that the ones they do like are already part of the software (at least the public beta assumption). Let's see how many beta testers write apple/fill out bug reports...