This is certainly a high-profile breach, but not apparently immediately catastrophic. However, it does provide a number of lessons for organizations and developers building smartphone applications (iPhone, iPad, Android, Blackberry, Windows Mobile, etc) All of the issues with the AT&T/Apple infrastructure for the iPad are known web application security issues. Smartphone developers need to learn from the past or they are going to repeat the mistakes of web application and AJAX/RIA application developers.

I put together some more in-depth comments here:
4 Lessons From the AT&T/Apple Data Breach for Smartphone App Developers

--Dan
@danielcornell