This aim of this patch was quite simple. Graphics processors with a vendor ID of 0x10de (which means one from NVIDIA Corporation) it would attempt to auto-configure the server to use NVIDIA's binary driver (if installed) before defaulting to the open-source xf86-video-nv driver. This patch had nothing to do with making the X Server require this binary blob or anything along those lines, but if the proprietary NVIDIA driver is present, the server would use it. This would allow the NVIDIA driver to be used without having a xorg.conf file present or manually specifying the driver to load. The xorg.conf file will eventually be removed in favor of greater auto-configuration and other persistent driver options. Some Linux vendors have already begun shipping their distributions without this configuration file by default.
Aaron Plattner's reasoning for this patch was that if the user has chosen to install the binary driver from NVIDIA for enabling 3D acceleration, it should be automatically used. It'd work out nice for a new user who wishes to use the binary NVIDIA driver to play games or use Compiz, but does it teach them anything about free software? David Airlie was the one that proposed this patch be reverted on the basis that there should be no auto-configure support for drivers that don't ship with X.Org.
Daniel Stone had also added in that this patch is "partially pointless" and adds a greater burden onto the X.Org developers. Daniel's standing is that this patch shouldn't belong in the master development branch, considering the common ABI breaks with new X Server versions and the lag time it takes NVIDIA to support these updates. However, in the event the NVIDIA driver does break, it should proceed to load the (open-source) "nv" driver.
To the desktop Linux user, the problem with this official open-source NVIDIA driver is that it contains only very basic card functionality and is limited to 2D acceleration. The code to this driver has also been intentionally obfuscated by NVIDIA engineers. Unfortunately, the community reverse-engineered Nouveau driver isn't yet in a state to become the open-source default for X.Org.
Following additional bickering, this NVIDIA patch ended up being eliminated. The thread regarding this auto-configure patch can be read on the X.Org mailing list.