Do you remember when Steve Jobs got in front of an audience and said that he wanted to be sure all applications for the iPhone would be good citizens, and to raise the bar for user experiences, all apps must be digitally signed, and approved by Apple, and that he implied that using the SDK like a good developer will enforce good behaviour?
What does it mean when an application downloaded via the Apps Store, digitally signed by the developer, built using the official SDK, crashes upon launch, and will also cause the entire phone to require a restart?
That said, iPhone OS 2.0 is the new hotness.