Tabs on top or tabs at the bottom? - That is the question.
Based on these leaked screenshots, it seems that Mozilla is having a bit of a dilemma in choosing whether to put the tabs of the upcoming version of its popular browser, Firefox 4, on top or at the bottom :
Tabs at the bottom
Tabs on top
Tabs at the bottom, on the other hand, is not necessarily a bad thing. Some users prefer this because it cuts the mouse distance from the browser space to tabs.
While this dilemma is enough a topic for a meaningful debate, I'd say, if Mozilla can offer the option, let the users decide where they want the tabs to be.