Well, this delay could be a good thing... remember how Half-life 2 was supposed to be? Sure there was a good amount of cool things that was cut (I want mah flare gun!!

), but ultimately their "revision" made the game better, more streamlined; they removed the redundant guns, made the atmosphere somewhat less 'in your face' and changed Alyx's design from that of a generic video-game female sidekick to a more realistic character.
They aren't delaying the game because they spent all of their money on cake, no, they do this sort of thing because they believe they can make a good game even better, and normally they are correct.