Sorry, I don't want to sound rude, but this is not just about testing the game... for us sure, we want to see how the game function at it's current state, obviously, but a stress test is more about testing the server, like how it can handle stuffs... Clearly I'm not a tech guy, I have no idea what it takes and all that, but its just common sense to figure what a stress test means. They announced the Open Stress Test, not the Open Beta or something like that.
If you just scroll up a bit you'll see the answer to that question.