did it look like this [1]? that's the UX nightly available at [2]. it's a new theme they're working on, but it's got a few versions to go before it makes it into stable. i'm loving it, but they're removing/changing a couple of customization features so people are freaking out. we'll see what the final product ends up looking like.
It's not just the user interface, it's that (for example) they don't QUITE completely ignore mac (emacs) keybindings (e.g. ctrl-a should move to beginning of PARAGRAPH, but either moves to the beginning of the visual line in the textbox, or highlights whatever you've searched for if you're that unlikely). This is far worse behavior, and it's been like this for years!
Actually this tab style dates back to at least Firefox 3. I didn't check further back. It looks like XUL can't do it the right way, and they don't care enough to do it right.
