As in other areas the question is, 'Why are the women doing this?' If the
answer is because they want to be like men, equality and all, then Reb
Moshe (in Orach Chaim 4: 49) has said it is Usser (Forbidden) .
I have been told by people who lived in Europe, that there was such a thing
as a "Vibisha Shul' ( a womens shul). The women wouldn't daven in the same
shul as men, rather they had there own place where they would gather to
read from the 'Tzena U'rena' ( a commentary on Chumash). They did not have
a Chazen or read from the torah. This was NOT done to be equal to men, but
to serve Hashem to the best of there abilities. Most of these women were
older, they didn't have small children, and most could not read hebrew. The
Tzena U'rena was written in Yiddish, the language they all spoke.
Dovid