This is another instance of the difference between NIC & NPC...NPC makes rules. NIC is mainly an information source for its members and doesn't really tell them what to do. It's always been that way and I don't know why the fraternities that decided to go dry (or NPC for that matter) thought it would change.
Here are the alcohol free housing fraternities at present (thanks thetachi.org):
Alpha Kappa Lambda
www.akl.org
Delta Sigma Phi
www.deltasig.org
Delta Upsilon
www.deltau.org
FarmHouse
www.farmhouse.org
Kappa Delta Phi
www.kappadeltaphi.org
Phi Delta Theta
www.phideltatheta.org
Phi Gamma Delta
www.phigam.org
Phi Kappa Sigma
www.pks.org
Phi Kappa Theta
www.phikappatheta.org
Sigma Nu
www.sigmanu.org
Theta Chi
www.thetachi.org
From what I remember from past discussions on this, Farmhouse has ALWAYS been dry, like since they started having houses. Sigma Nu can waive the dryness if the chapter meets certain grade & other requirements I believe (ktsnake, please correct me if I'm wrong). Additionally, when some other groups recharter a chapter for disciplinary reasons the chapter housing must be alcohol free.
I'm sure a lot of people remember the cry "Dry by 2000"....well here it is, 2004 and the majority of NIC groups are far from that. I think that NPC could have chosen other ways to "support" these groups (for example, at least one social event a month must be alcohol free, if you have alcohol free fraternities at your school have it with them) rather than doing something that has had such far reaching consequences.