E! News [1] reports rumors that Charlize Theron is director George Miller's top choice for the female lead in MAD MAX 4. The first Mel Gibson-minus film in the franchise is in the very early stages with plot and even character names not even being revealed to auditioning actors. Tom Hardy (BLACK HAWK DOWN) is also said to be up for a top role as well.
Links:
[1] http://www.eonline.com/uberblog/b150027_charlize_theron_mad_maxine.html