I with you on the bomb theory: New, well-maintained plane. Two months after 9/11. Osama said more planes would fall. Airport security still a joke. New York airports are rife with Mob activity, illegal aliens, and corruption. Baggage bombs are not rocket science - the recipe is no doubt in that "terror manual." New York is Osama's favorite target. He likes layered multiple attacks.
Weight all that against the odds that a random catastorphic failure would occur in this time, in that location, on that kind of plane, and you would bet real money on it having been a bomb.
Witnesses saying the tail section came off? Several heard a loud pop? Yeah, I believe the engine fell off, but engines don't just fall off unless their has been some kind of catastrophic maintenance error -- and that's HIGHLY unlikely with the current condition of the airlines. These guys are going over these planes with a fine tooth comb, and then the pilot inspects the engines on the tarmac before boarding.
It's widely known that airports x-ray only a FRACTION of the bags that are checked. They complain that it would take TOO LONG to X-RAY all bags for bombs. No one knows for sure what happened here, but given the propensity of the media, gov't, et al. to hide terrorist activity (TWA 800), I'm going to be extremely cynical. Also bear in mind that Ashcroft just got done talking about how relieved he was that we passed through two state of high alert with no incidents...