From the specs i have seen so far, it seems more like a PA3x plus.

Same style engine
Slightly upgraded sound engine, but the improtant features that make the Kronos stand out did not make it to PA4x (sample streaming, piano damper and string resonance)
And the whole PCM memmory is a whopping 400 MB with another 400 Mb for user samples.

We have to see how this works out for the soundquallity..

But Korg italy did not use the technical advantage Korg has with their Kronos in the PA3x..

Maybe its just me, but they are again using the same old hardware (as all other arranger manufactorers) to maximize proffits.