Jennifer - I completely agree, the things that happened 25 years ago should have been dealt with then, the fact that a group that did that was allowed to linger makes everyone look bad.
I can't say what will happen with the fraternities - some will stay on a non-admin supported campus and some will not. As far as the sororities however, DZ will probably pull out, as they did at SCU, just because that is in their constitution. If the girls have a strong sisterhood they can probably make it together as a local. Since the other 2 sororities are already local I don't see a problem with it.
madmax is right, if you are public you can live wherever you want. If your school accepts ANY $$$ in federal funding they are stepping on your rights.
http://dke.org/roar.html has quite a bit of info on the situations at the other colleges up there - check it out. Good luck to you all and hang in there.