First up, this new Nouveau DDX adds GLAMOR support as long as you're on X.Org Server 1.16 or newer (it doesn't use the external GLAMOR library). The GLAMOR support is optional for all NVIDIA hardware as a means of accelerating 2D over OpenGL while for Maxwell hardware and future generations it's now a requirement. Like AMD with their GCN HD 7000 series hardware and newer, they're no longer writing 2D code-paths but letting their OpenGL enablement take care of everything.
With the GLAMOR support also comes the Maxwell enablement of the GeForce GTX 750 series inside Nouveau. Going back to May there's been the Maxwell support in Nouveau's Gallium3D within mainline Mesa and since the Linux 3.15 kernel has been the start of open-source Maxwell support. Nouveau Maxwell support is still evolving but they're continuing to make progress.
The xf86-video-nouveau release also has support for server managed FDs for supporting the X.Org Server running without root privileges. Also ushered in by this update is DRI3 and Present extension support. Other changes include vsync KMS page-flipping performance fixes (on Linux 3.13 and newer), multi-display vsync/vblank/swap/time-stamping fixes, multi X screen support fixes, Zaphod support for multiple outputs per X screen, EXA NV10 fixes, swaps are now synced to vblanks by default (using the GLXVblank option in the xorg.conf), and pseudo triple-buffering is now disabled by default.
The straightforward change-log can be read by this Git commit tagging xf86-video-nouveau 1.0.11.