The reason is that the press is waiting for Apple to drop that next hit as they did with the iPhone, iPod etc. They want to be there when it happens and report

The reason is that the press is waiting for Apple to drop that next hit as they did with the iPhone, iPod etc. They want to be there when it happens and report it first. The thing is that in between those hits, you have down periods where Apple is just going to put out incremental updates, add colors, change sizes and change materials. When that hit drops, every press outlet wants to say "This is where you heard it first."