Vaporware, pure and simple. Hewlett-Packard and Intel have been jointly "developing" this for what, almost a decade now? 1997-ish roadmaps have said this will be ready in spring of 1998. So much for that. Lately, Intel has been quietly downing the said clock speed of the beast from GHz to 800MHz and I think I might have heard 500MHz, to say nothing of the Pentium 4 recall.
And when it does come out (2006, anyone? :P), they're going to cost you an arm and a leg. Marketed for high-end servers only. Intel is assholish like that.
See also:
Merced,
EPIC (way down at the bottom there)