My guess is they're not including Skype for many of the same reasons they don't include Flash. They don't want to be in a position where they are depending on one single company to fix things so they can release new products.
That sounds about right... but doesn't that scare away lots of good ideas? Don't develop an idea that would be a great selling point for the iPhone, cause Apple will see that as a possible future dependency, stall your app from getting in the store and do it themselves in the next update. If Layar really gets moving, how long till Apple "does AR right" and then kicks them off for "duplicating built-in features"?
