We use privacy from a another provider. I have looked at the privacy (and potential cost to switch some of our domain-related suppliers), and it's not likely something we'll be changing anytime soon. I also have a pretty good idea of what other providers there are and what they charge.
ICANN also has plans to require a separate type of accreditation for whois privacy providers, but the project has stalled for a while. I was part of an initial working group from the registrars' side.