The only use I had of WHOIS having my details is getting a random phone call from a chap wanting to buy my domain name off me, which back in 2003 I made about £600 for. Personally I'll be glad to see the back of it as I think it's completely unnecessary to have those details exposed. It's made a mockery of with privacy services anyway and I balk at the cost of those on top of the domain. It's not going to make any difference to anyone having this shut off, only the registrar and the naming authority need my details.
What is going to be affected is verified SSL certificates, although I imagine there's an opportunity for registrars to make some money out of a verification API. I'm sure someone will be right on that.