I've already been writing about some of the changes for Linux 4.5 but you may have noticed that Nouveau hadn't been mentioned... Well, that's because there doesn't even seem to be a 4.5/-next branch for this new kernel cycle where its merge window will open next week.
The Nouveau Linux DRM repository doesn't have any new material and the latest activity are Linux 4.4 fixes from six weeks ago. There is also Ben Skegg's Nouveau GitHub and his personal FD.o repository both without any apparent new material for Linux 4.5.
More telling is that the merge window opens next week and there hasn't been any new Nouveau code queued in DRM-Next, particularly as since last year the DRM-Next pull requests now need to be submitted sooner than just a few days before the start of a new merge window. So sadly it's not looking like there will be any big re-clocking work to find with Linux 4.5 nor NVIDIA's long-awaited changes for having the signed firmware support for being able to handle open-source hardware acceleration on the GeForce GTX 900 series.