> People are already talking about 64-bit ARM, though. Intel needs to move fast if x32 is going to matter.
That is a bit misleading. x32 is an ABI for 64 bit processors. ARM 64-bit, when it becomes a reality, is likely to perform much like x32 on all applications that do not make heavy use of pointers, and substantially slower than x32 on those.
If x32 is useful, something similar for ARM 64-bit is likely to be useful for exactly the same reason. It might even predominate over a pure 64 bit ARM ABI. How many portable devices are likely to need to address more than 4 GB per process?