Good thought, but im sure that sony has in some way encrypted anything they have on the sony store. Therefore you need a ps3 in order to get anything going.
When I purchased Flow it said something about "Activating" or "certifying" when it had downloaded the game. We would more than likely have to encrypt the game in that same fashion to make the ps3 think its a real sony game.
But I could be wrong on all of that. It just seems to easy if it were that way.
BTW how do you get on the store? URL? if allowed?