mmmMMMmmm that Powerstation would make a fantastic OS4 machine. Assuming OS4 could handle multiple cores (which I suspect it can't) - and assuming we had useful apps that made use of all that power. It certainly makes the SAM seem extortionately expensive though.
I'd imagine the Powerstation would sell many more units than the SAM, allowing slightly better economies of scale than ACube get from the SAM boards. A complete SAM system, while much less powerful, starts at €719 which isn't all that bad for a system that hopes to sell a few thousand units at best! Currently OS4 does not support multiple cores/CPUs, but it is planned for a future update to the OS. This kind of support requires a great deal of work on the OS at a very low level, so it won't be today or tomorrow, but it'll come...