Just heard this on fnc-
http://www.foxnews.com/story/0,2933,586581,00.html
right after it happened f.n.c. was reporting that the plane crashed into a building that housed the local f.b.i. offices, among others. they repeated this portion a couple of times. a few minutes later they realized that the plane had hit a different building, not the one that housed the f.b.i. and they had to change the story.
the 'impression' i got from the f.n.c. anchor re plane hitting the f.b.i. building was that he/they were disappointed that the f.b.i. wasn't in the hit building. maybe it would have indicated a terrorism connection, a connection that they could lay at the feet of a certain u.s. president. but it wasn't to be. so far.
like i said, an 'impression', no validation.
edit- now f.n.c. anchor or a source is speculating that the pilot may have targeted the local i.r.s. offices, in the same building or near it, instead.