Ari Fleischer said there were no "unusual communications" from the cockpit. Ari said this about three times. To me, that's pretty insistent.
The airlines would be keeping some info quiet until they find out exactly what happened, and even after.
If it was an 'engine failure', then you try to limit your liability (and your insurance company's liability) by keeping any info that hurt's your case to a minimum.
If they stated right now that "Hey, yeah, mechanic "x" worked on that very engine, it was having trouble and we thought we would just wait a few more trips before fixing it", I guarantee their insurance carrier would drop them like a hot potato.
First rule during any accident is "keep your mouth shut as much as possible".
Second rule is "answer only the question asked".
Until a complete investigation proves what went wrong, The airline is just protecting it's stockholders and insurance carriers, and future by limiting info given out to anyone. Now, if they had a hint that it was terrorist related, I believe they would show complete candor.
That is why it was probably "faulty engine", "bad diagnosis by mechanic to let it go without major repair".
This could also have been a result of recent incidents. The airline might have been more concerned with keeping passengers happy (get em in the air and on their way) due to low profits (or none) lately. I.E. Money over safety. You won't be seeing them getting on T.V. and announcing that as the cause !
Earlier I was convinced this was a bomb. Now I am fairly sure it wasn't. Old plane, old engine with history of failure, delayed takeoff due to mechanical malfunction -- sounds like a classic catastrophic engine failure. The good news is we should know very quickly one way or the other. There are too many media people crawling all over this scene for there to be any coverup.
We have to be able to realize that September 11 did not stop planes from failing, people from being nuts and committing weird and gruesome crimes that have nothing to do with terrorism, Hazmat trucks being stolen for joyrides, and other assorted bad things.