Some say it's purely a marketing-driven issue. I, however, think that there are some scents too femme for me to wear, and I know a few women who find some scents too butch. So it's a personal call - but I would also agree that there's a vast swath of scents that can easily be worn by both genders.
+1 There are no "woman's" scents, just scents that make you smell like a woman. SMN Musk today - this is a powdery musk with a little note of spice in there. Not really musky but not bad. Going in the swap box.