Preview at WWDC likely in June, followed by September launch.
Apple-Owned 'iTun.es' Domain Could Be Used as iTunes Link Shortener
Example of Tweet generated from Ping
One MacRumors reader realized that the new integration with Twitter could make a good opportunity for Apple to deploy its own link shortener to help fit its links into the character restrictions imposed by Twitter. The reader let us know that he had discovered that iTun.es forwards to Apple's site and theorized that the domain could be used by Apple for just such a service.
Registration information for iTun.es
We dug into the situation a bit further and determined that the iTun.es domain is in fact registered to Apple via MarkMonitor, the brand management firm Apple uses to handle all of its domain registrations. The domain was registered to Apple in December 2006, meaning that Apple has not just recently moved to lock down the domain as a link shortener, but the new tie-in with Twitter does provide an excellent opportunity for Apple to roll out a service using the domain.