"US consumers just aren't concerned with lightweight frames anymore, since the difference in weight between an aluminum frame and steel one is an almost-full water bottle." said an un-named source. "Consumers are looking for steel frames that will last them a lifetime, and we're not going to sell carbon frames anymore, since they don't fit that need."
Clearly this a big turn of events for Trek. For those looking for that that carbon fiber look, they will start offering special faux-fiber paint effects for fork and seat posts.