The Steam sale and Dead Space

I've been buying the odd game on Steam, throughout their Christmas sale. Today is the last day, and Dead Space is half price or something. So I thought, what the heck.

Clicking through from the sale page..

To the actual game page, where amongst the screenshots, system requirements and the like it says the following..

I don't understand what this means. But I think it means that if I were to buy the game, it would be a rental for an indeterminate period of no less than a month. Are they trying to make people to pirate their games just so they get what they paid for in a form that's actually playable?