GPU would be easy - essentially the PS5 is a variant of the RX6700, it's likely a variant of the RX7700 would fit the bill, offering double the TFLOPS when downclocked slightly to reduce power usage/cooling requirements and improve reliability over time.
I suspect the CPU will be a mild upgrade, probably to Zen3/Zen3+ standard - I can't see anything radical happening like 3D Cache being added (due to cost and potentially being too different in performance in some cases), or it being a newer architecture like Zen5 (simply because of the lack of availability of those parts at present)