It would certainly appear — with Leon Panetta lifting (most) restrictions for women in combat — that the legal rationale for excluding women from registering for the draft is gone. From Selective Service:
Not sure if I totally agree. The Supreme Court has ruled men-only registration is constitutional. Since any draft would be to used to supply Army ground combat troops, and women were not allowed to serve in that capacity, there was no logical reason to include them in the draft and excluding them didn't violate the due process clause of the Constitution. But under the ew policy women would be allowed to volunteer for combat, not required to face combat if so ordered as the men are. What's the point of drafting a bunch of women if the vast majority of them won't seek combat?
There's moral and philosophical justification for an all-inclusive registration, though, even if the legal and constitutional reasoning can be challenged. Adult men and women are equal as citizens, are they not? That should mean both equal rights and equal responsibilities. Perhaps including women will make policymakers see what they so far have been unable to: In the absence of a national emergency, there should be no draft contemplated, so draft registration is pointless.
This is a gigantic change in policy, by the way, that involves the whole country reordering its thinking of the role of women in society. The role of men, too, come to think of it. How remarkable that a single person -- and an appointed rather than elected one at that -- can bring it about on his own. It's like we're on the Startship Enterprise and Capt. Picard has spoken: "Make it so."