Yep, we all got screwed alright. It really sucks playing Team Fortress 2 three weeks early and enjoying the hell out of it.
YOU didn't get screwed because being the Valve lapdog that you are, you would have paid twice the price for just a screenshot of TF2 three weeks early. The people who are getting screwed are the ones who want to try TF2 without having to buy it first especially without having to buy the whole Orange Box when all they really want is TF2.
If the game is as good as you claim, Valve would have nothing to lose by giving a free demo because most people would end up buying it. This is just a greedy tactic by Valve to scam money out of people who end up not liking the game or who wouldn't have otherwise bought the whole package.