Or Apple could just be cautious about the new connector. This is their first new dock connector since 2005. They may want to see it (or third-party accessories

Or Apple could just be cautious about the new connector. This is their first new dock connector since 2005. They may want to see it (or third-party accessories for it) in the field before approving third-party adapters. There may be electrical details that are tricky to get right. And so on. Normally I'm quite willing to believe the worst of Apple, but here there are too many reasonable explanations for limiting third-party adapters and cables for the moment. If the limitations end up not being temporary, that would be another story, but until then...