They see that Linux has gained importance for them after Valve has announced that they will be going for Linux.
This move is generally regarded as positive in the Linux community but Linus Torvalds is not quite ready to apologize for his finger -yet:
Torvalds has responded to Ars, saying he's optimistic but not quite ready to apologize to Nvidia. "We'll see," Torvalds wrote in an e-mail. "I'm cautiously optimistic that this is a real shift in how Nvidia perceives Linux. The actual docs released so far are fairly limited, and in themselves they wouldn't be a big thing, but if Nvidia really does follow up and start opening up more, that would certainly be great.
They've already been much better in the ARM SoC space than they were on the more traditional GPU side, and I really hope that some day I can just apologize for ever giving them the finger.