The whois information reveals that the domain points to Apple's nameservers, and correctly redirects to http://www.apple.com/iphone. The Whois owner information remains hidden under ownership by " Domains by Proxy, Inc."
Domain Name: IPHONE.COM
Registrar: GO DADDY SOFTWARE, INC.
Whois Server: whois.godaddy.com
Referral URL: http://registrar.godaddy.com
Name Server: NSERVER.APPLE.COM
Name Server: NSERVER2.APPLE.COM
Name Server: NSERVER3.APPLE.COM
Name Server: NSERVER4.APPLE.COM
Updated Date: 29-jun-2007
Creation Date: 24-aug-1995
Expiration Date: 23-aug-2008
MyPhoneWar.com speculates that this is the result of trademark/legal action, but it is also possible that Apple simply purchased the name from the previous owner.
Apple's iPod.com domain was also owned by a 3rd party until the day of the iPod launch at which time it was transitioned over to Apple.