It seems that the powerplant will use the same 4.65-inch bore as the traditional Porsche flat six. The unit will use the latest technologies in order to offer a high level of efficiency, so we'll probably get piezo-guided direct injection, as well as a small turbine.
As always with Porsche, there will be multiple versions of the engine. The "normal" ones are expected to deliver between 200 and 300 hp, and we might also receive one that delivers as much as 380 hp.
We have to note that the upcoming powerplant has a difficult job, as it will appear in a time when hot hatches have no shame in taking on sports cars and Porsche couldn't afford one of its models being left in the dust of a Renault Megane RS, for example.