They don't need to open source the whole toolchain, just the parts of the code they own/wrote themselves. For the parts of the toolchain they can provide documentation (writing it out if this documentation needed to be created/revised) to fill in the missing pieces.

> "I don't see how they could do any of the above tasks for less than the price of this Kickstarter."

You seem to be overlooking that reverse engineering hardware drivers is a hugely inefficient process. People only do it out of necessity. Furthermore, the Kickstarter has set modest goals of enhancing the work that has already been done (MPEG2 acceleration, etc...), the end result is not a driver that can be used for more general purpose graphics acceleration (e.g. no OpenGL driver). That's not to say it isn't a good step forward, I welcome it, but you should be aware that there's a long road ahead after the work for the Kickstarter has been completed. If you don't believe me, look at the ongoing work being done by the Nouveau team.