Oh no not again!
If there are there shouldnt be, today were living in a sociaty where everybody should be treated the same (although they're not) weather your a particular colour, sex, or even if your a lawyer you can still train with all the other human beans.
I beleive there have been many threads on aikiweb about this and they have ranted on and on about the same stuff over again some women think its a great idea so they dont have to put up with men, some men think its a great idea for the same reason, some for religious perposes, some for the fact that they think women are inferior or that men just plain cannot understand women (who can)
aikido is about the art, it doesnt matter who you train with, it doesnt matter because weather you have breasts or not has no influence on wheather you can throw someone 20 ft or drop a guy like a sack of spuds.
at our school if your black, white, green, pink, female, male ,N/A or just plain nutz i'm still gonna practace yonkyo on yer and i aint gonna ask does it hurt because it bloody well should.