The idea isn't new, it was first implemented by http://www.adcaptcher.com/ about an year ago.

whois information has nothing to do with DNS. You should use whois amazon.com -h whois.networksolutions.com to get proper info. What you saw is a result of wildcard search in wrong whois server.

The DNS servers for a domain name are announced in root DNS servers - and there, everything is fine. For example, dig NS amazon.com @a.gtld-servers.net return correct DNS servers: udns1.ultradns.net. and udns2.

However, dnsreport show lots of errors with nameservers:
http://private.dnsstuff.com/tools/dnsreportsmpl.ch?domain=amazon.com