Are these formal ICANN rule-changes, or just how iwantmyname is choosing to enforce the verification aspect of domain ownership? Seems like what they're saying they may do is replace your domain with some lead-generation landing-page similar to what many domain registrars do upon registering a new domain prior to modifying the DNS settings.
I've spoken to Timo and the others on the team at iwantmyname before and they're all pretty laid back so I can't imagine them doing this unless they really had to.
Edit. This seems to be a more legal-like explanation of the relevant rules from a registrar called enom.
http://www.comprotex.com/icann.html
As commented above[1] it looks like this is required by a new contract which is required for registrars to sell all of these new (and imo, silly) TLDs such as .cab, .sexy, etc
No, this is incorrect - it is part of the new Registry Registrar Agreement that ICANN ratified earlier this year. It goes into effect 1 January. All accredited registrars will have to agree to it this year to retain their accreditation.
No, it's not. Any registrar on the 2013 RAA has to proactively validate and verify WHOIS data accuracy. Those still on the 2009 RAA only have to reactively validate and verify WHOIS data accuracy in response to complaints.