As an iPhone dev, I'm sure iPhone OS 2.0 isn't perfect. They pushed 8 beta builds into the hands of devs since march. They've been working on hugely aggressive timelines. There has to be defects. In all, however, I'm glad it's released.
With 10 million apps downloaded in the first weekend, it appears that the users are glad it's released too.
I used to develop for mobile Java, which took a long time to mature (not sure if it has matured, actually). They had a problem Apple doesn't have, inconsistencies across the thousands of devices. Still, I wonder if developing for iPhone would be like going back to the start again, with yet another immature platform.
Given not enough time, and too many eyeballs, all bugs are possible :D