[citation][nom]linus_torvalds_groupie[/nom]TA152H: Actually, it's the performance of Itanium that sucks, not the other way around. Microsoft said it sucks, Linus Torvalds(creator of Linux) said it sucks, who else do you need to hear it from?[/citation]
Linus Torvalds isn't always right, despite your apparent worship. He and another fellow have argued back and forth on the Itanium. Linus believes even a bad instruction set is OK, because over time it gets understood and works OK. Volume and time makes up for a lot of the problems, according to him.
The problem with Itanium is it's always way behind in manufacturing technology. It just moved to 65nm, whereas Intel has been using 32nm for x86 for months.
But, your point is irrelevant. Itanium has always been slower, for reasons mentioned above, but Microsoft supported it. Tukwila closes the gap, it doesn't make it bigger. But, the problem is, HP/UX and Oracle are roughly twice as fast on the Itanium as Windows and SQL Server. So no one wants it. Well, not enough people want it to make it feasible for Microsoft to keep developing it.