Sounds like a great idea, and I have to agree with the two points that posters brought up. While it is great for men to take so that they don't have to subject themselves to being "oops-ed" by their partners, it is also important for women to take responsibility for their own birth control because they, in the end, are the ones who end up with the pregnancy.
But I think for stable couples who have the trust, it's a great idea. Also, some women can't take birth control for health reasons so it gives them another option, again providing they have a trustworthy partner.
Jill