Will the already sold tickets fo Madonna's tour dates count for May 2011 to May 2012? If they don't count until the concerts happen, Madonna will more than likely top the list in 2013 but definitely not this year.
Gaga might be able to retain #1 female musician for another year, but I don't think it's gonna be cut and dry due to competition from her peers.
One of the entertainment shows (I think it was either for the Insider or ET) was advertising a preview of the new Forbes Celebrity 100 list. They mentioned Beyonce in the teaser which doesn't necessarily mean she was the top female artist on the list but it could mean that. So look out for the entertainment shows tonight.