How exactly will they be "grandfathering in" the current unlimited members? I guess this isn't a huge deal for me, as I live on a campus with wifi all around, I'll just have to start using it more often
Actually, you'll be allowed to continue to use your "unlimited" data plan even after your contract expires. However, after that, if you ever try to change anything about your plan or take advantage of introductory phone pricing you'll have to move to their updated tier plans.
That's how I understand it.
Does that include upgrading my phone?