One of the things I have noticed regarding the theories proposed by CNN and others is that they all seem to be missing one important facet. If there was a problem noted by the crew/customers, someone - many someones would have tried repeatedly to communicate those problems. This plane does not appear to have conflagrated in mid-air. All the other scenarios provide sufficient time for the crew, who had many different types of communicationa available to them, and those flying - there had to be 300 plus cell phones in eager hands - to call someone or to keep trying to call someone. That is the compelling bit of data in this scenario. If it didn't conflagrate immediately, and it doesn't appear to have done so, then any scenario provides time for notification/communication.
Even the air presssure issue, similar I suppose to the Payne Stewart incident - is it reasonable to think that of the 400 people onboard none of them would have time to protect themselves and call/notify??? That jet would have been in cell tower range soon and a kagillion calls would have been made. At least one of them, it would seem, would have been received. And the latest on CNN indicates the debris field is close to the flight path, so a Payne Stewart type incident appears to be ruled out, but not difinitively. A plane in those conditions, flying via computer, could go a thousand miles or more.