The last time the xf86-video-nv driver was updated was in early March -- just a couple weeks before NVIDIA announced it would stop supporting future ASICs in this driver nor would it deliver any support for features like DisplayPort. That March update didn't bring much to the table nor does this update that's coming out of NVIDIA's Santa Clara offices on a Friday afternoon.
The most notable change with this xf86-video-nv 2.1.18 driver update is that this DDX driver will no longer load if there is a kernel module bound already to the device, which makes it so this crufty driver will not interfere with Nouveau's DRM when loaded and already claiming the NVIDIA graphics card. Other changes include updating the PCI ID associations with different product names, a couple of bug-fixes, and cleaning some old code. Support for the now very old GeForce 7025/7050 GPUs was also added to this 2D-only driver to fix an old bug.
The release announcement and rather uninteresting change-log for the xf86-video-nv 2.1.18 driver can be read on xorg-announce. This xf86-video-nv driver update will really only be useful for those running an older Linux distribution with NVIDIA hardware and happen to be using this driver rather than the proprietary NVIDIA Linux driver that provides full 2D/3D/VDPAU acceleration. Most of the Linux distributions shipping this year are using the open-source Nouveau driver that provides kernel mode-setting support and a much greater set of features than what was ever provided by xf86-video-nv. Some Linux distributions are even now enabling Nouveau's Gallium3D driver for providing OpenGL acceleration. This xf86-video-nv driver update may also be of some benefit to those using other Unix-like operating systems such as FreeBSD or OpenSolaris where the Nouveau DRM driver has not yet been fully ported and enabled on such platforms.