the organization I work in had 4 Dell dual processor ia-64 systems.  After
several months of using them only one is still being used and that only as
a desktop system.  They have tried Win something and the redhat variant on
it.  2 people went back to using quad Xeon systems.  These things are
using Itanium 1 CPU's.  

I just stuck one in my office waiting for FreeBSD 5.0 release.  We've
tried giving them to other orgs in the company and nobody wants them.

my US$.02 worth observation