Kotaku - Did Valve Just Take Everyone For A Ride? Thanks nin.
This "game", though, violates that neutrality. A selection of games have sold through the roof this week (Portal 2 was #1 on Steam's charts, followed by the "The Potato Sack", the collection of indie games containing Portal 2 promotions, at #2), and sold purely because people wanted to play a Valve game early. While the indie developers involved are getting a nice bonus, proceeds from each sale are still going to, yes, Valve. To promote a game Valve developed. At the expense of other third-party games.

So people were sold games believing that purchasing them would let them get at Portal 2 early. And for all their trouble got the game...a few hours early. Making matters worse is the fact the console versions of the game, shipping on physical discs, are already finding their ways into people's homes one way or another (I've already got a copy on 360, for example, while my PC version sits at "pre-load"), and those people didn't have to spend an extra cent.