Mozilla Firefox 4.0 mockup screenshots released

It has been a month since mozilla released firefox 3.5 and its been 3 weeks since mozila released the screenshots of 3.7, and now Mozilla wiki have posted the screenshots of 4.0. They have posted two version of it

Version A - Tabs-on-Bottom
and
Version B - Tabs-on-Top

But,mozilla is still thinking on whether to keep the tabs-on-top or tabs-0n-bottom. The tabs on top, looks almost like Google Chrome. Here are the screenshots of them

Version A - Tabs-on-Bottom

Version B - Tabs-on-Top




Combo Stop/Refresh/Go Button.


Here are the Positives and negatives of 4.0 as explained by Mozilla

Positives

* Save Vertical Space
* Efficiency/Remove Visual Complexity - Right now the tabs have to be connected to something. So we are adding an extra visual element for them to connect to.
* Shorter Mouse Distance to Page Controls


Negatives

* Breaks Consistency/Familiarity - Moving things confuses existing users.
* Title is MIA - With the space removed from the titlebar you only get the truncated version in the tab.
* Longer Mouse Distance to Tabs - Takes longer to mouse to a tab.
* Lost Space - Sandwiched in between the application icon and the window widgets you lose some space.

Whatever it is, this looks great to me. I personally loved it, and i'm waiting for it to get released.