Your response is kind of funny when coupled with your following post requiring someone good looking in the role. Since that's basically the entirety of the character: a man's man superspy.

Bond has pretty much been an icon for masculinity. It's a main part of his character. They toyed with it in these last ones by making his blunt instrument alpha male-ness an issue. Swapping genders for Bond would make as much impact IMO as changing Ripley or Sarah Connor into men. Changing Bond into a woman would be like changing Bourne into someone without amensia - you can do it but it's a completely different movie and really has very little to do with the franchise.

Usually, I do think you can switch genders and not make a huge difference (ala Ghostbusters) but, in some cases, the gender is a part of the character.