To be precise, Win64 for Itanium contained a binary blob provided by Intel, which worked as an x86 emulator. I think some Itaniums used it and others had hardware to run x86 code.
Yeah, thats correct. The some (most?) of the first series (merced) of itaniums had hardware to help accelerate the emulation of x86 instructions. I don't know about the later iterations of it though as I've only run OpenVMS on the later ones and not Windows.
The early Itaniums had hardware support for x86; the later ones relied on software emulation that outperformed the previous hardware support.