I am particularly curious to see what packaging options this device will come in. I am wondering if this product is aimed at the Cortex M market, or the lower end of the Cortex A series? If it is aimed at the M, say M4F with a higher clock speed, it would be interesting to see this type of device in a QFN and QFP. If it is competing with the A series, I expect that this will only be available as a BGA.
I don't know anything, except that AMD64 introduced a lot more than just a bigger address space. IA32 is really not a good/modern ISA, and it would be quite strange to see Intel falling back 10+ years. one real register, stack-based x87, no vectorization, etc. at the time, 64b extensions were justified as not adding a lot of chip complexity - of course that's relative to OoO/superscalar stuff.
Getting better opportunities on the security and embedded internet stack because of very long stay in the computing environment will be a very good plus point for Intel on getting proven in IoT Processor segment.