What you're saying is quite right. Nvidia wouldn't sell they brand new, super hyped cards to a lower price just because 3000 people on massdrop has committed to buy it. They'll probably sell out on launch day anyway.
But wouldn't this be the perfect moment for us to get a drop on the 980 or 970? The amount of buyers on those cards will drop drastically on launch and going to nvidia and saying " Those old cards over there in the corner, we would like 3-4 thousand of those". That's how you get a good deal.