will the linux version still show the window frame on top of the tabs?

Update: seems so http://people.mozilla.org/~shorlander/blog-images/australis-...

why didnt they take this chance to fix this, chromium does it>

Chromium does it, to a pretty useless extent. With so many window managers, it's pretty hard to draw correct window borders on every machine, and Chromium doesn't even try: with Ubuntu, for example, it draws the titlebar buttons in the "wrong" corner.

Let's face it, the Linux version will only show the window frame if you choose to draw it: not all do (with tiling wm's it's pretty rare, even). Firefox is easy to customize, which allows every distribution to match it looks to whatever theme they use. Linux doesn't have the DE like OSX and Windows do.

If you use Gnome I've been reasonably happy with htitle.

https://addons.mozilla.org/en-US/firefox/addon/htitle/

The Unity DE for Ubuntu hides the frame when it's maximized, and integrates the menus into the global bar...

i just hide the title bar with the window manager, its linux after all ;-)