The PC release is now on Steam Greenlight, so please vote for it:
Frankly, I've put it up more as a cheap way to advertise the game ahead of its release than in any expectation of it getting greenlit, but I certainly wouldn't complain if it did make it on to Steam proper. You never know, stranger things have happened (like when it rained frogs that time in Brazil).
Anyway, if all goes to plan you should be able to buy it somewhere else sometime in the beginning of September. There may even be more than one way to get hold of it at release...