NVIDIA to provide documentation for Nouveau

You are comparing apples to oranges really: pricing of GTX Titan is so high because it's seen as the fastest card on the planet at the moment, so it can milk as much money from the "I don't care about the price of the GPU" buyers as possible.

Whether Nvidia has an answer to future AMD products or not remains to be seen, but the article you linked to was not very convincing to me.

In any case we all agree that nVidia opening up is very good news!