AMD's Sledgehammer for one. Personally I am betting that when games hit the wall with 32-bit addressing, AMD will be what they move to. And with the listed performance numbers, I would wonder if TransMeta can emulate Itanium faster than Itanium runs...
And if the performance problems are bad enough that people are willing to throw away x86 compatibility, don't forget that there are several 64-bit chips out there which could potentially move from their current roles in servers to general desktop use.
Cheers,
Ben