Discogoddess,
I usually stay out of the hazing/pledging conversations because 1) I'm not a member of a sorority and 2) they have been beaten into the ground and rarely does someone's opinion change. That being said, here I go anyway
I understand what you are saying about a moratorium on undergrad membership, but I don't think that will work because of the way people have romanticized pledging. Above ground pledging in the NPHC was banned (please correct me if I am wrong) 1990. The average college student (at 19-20 yrs old) was 9 or 10!! They shouldn't (really) know anything about pledging, but they talk about how they want to be pledged. So, how do they know what that means? Of course movies like School Daze and shows like A Different World have ficitionalized above ground pledging, but I think most of them have gotten an idea of what 'pledging' is all about from members of BGLOs--"old heads" if you will--talking about their experiences--even when they talk about how hazing/pledging was a bad thing. People like sharing war stories. When they do, they elevate the experiences to mythical proportions. When you are 19-20 and some one you respect talks about how "hard" they worked for their letters, how they never got any sleep, all the things they went through, etc, the impressionable 19 year old wants to experience the same thing so he/she can be "just like them". Even if the person is saying 'don't do this' those stories can, sound like something you would want to do too.
If there is going to be a moratorium, it should be on sharing stories on how you came in. If that stopped people would stop wanting to 'pledge'.