That's not really how the story goes, though. Intel spent a lot of effort on getting Itanium to succeed, and they really dragged their feet into x86-64. It was the market that decided that the price/performance of Itanium wasn't worth it.
Thats how a lot of people tell the story, but I just don't agree with it. There is zero evidence that the market killed Itanium when Intel was already trying to kill it because it was eating into Xeon sales on high end platforms.