Ubuntu's policy is that we do not update video drivers to new versions after a release, except for bug fixes. However, often times users need newer drivers. This page documents several official and semi-official channels for distributing driver updates.
nvidia-current-updates / fglrx-updates
The -updates packages provide rolling driver upgrades. Users who install this package will be automatically upgraded to new stable drivers as they become available. This package can be installed via the Additional Drivers option in System Settings.
When the user upgrades to a new Ubuntu distribution release, they will be kept on nvidia-current-updates. Initially at release we'll have the same version as in nvidia-current; we will then track any new bugfix releases on that major version. Then when a new major version has been released as stable we will update to that.
SRU Policy: We test these updates thoroughly before distributing them, but because the drivers are closed source binary blobs we can never be 100% certain that they are completely regression-free. For this specific package, a certain degree of regression has been deemed acceptable, for the following reasons: 1) It's a binary blob video driver so we can't fix issues anyway, 2) It's optional, and 2) Video drivers are rarely a 100% improvement for all hardware.
SRUs are filed in the usual way, but our threshold for blocking on regressions is higher, so the update can be accepted to -updates even if there are a few reports of possible problems, so long as sufficient testing in -proposed has been done to confirm the driver will work properly for the vast majority. However, we should still block if any of the reports are substantiated.
Certain applications and games may need features or fixes that are available only in beta versions of the -nvidia driver. The nvidia-experimental-NNN package provides access to these drivers.
The experimental driver package will track one major driver version from beta to release. If NVIDIA makes multiple minor beta releases we may include one or more of those. When the beta is over and the final driver release made we will update the package to the release version. When the user upgrades to a new Ubuntu distribution release, they will be moved off of the nvidia-experimental-NNN package to nvidia-current.
FFe Policy: Nothing included in the Ubuntu release will depend on the experimental driver. Implicit in the Tech Board decision, no FFe is required to add or update an nvidia-experimental package.
MIR Policy: All new nvidia-experimental-NNN packages use the same packaging code, only the version number (and blobs) change. The master MIR bug for this package series is bug #1050674. As per TB, no further (explicit) MIR review is required beyond this.
NEW Package Policy: As per TB, the NEW authorization for SRUs is implicit in the general delegation to ubuntu-sru. Thus the NEW package review can be handled as part of the SRU review.
SRU Policy: A prominent warning is included in the Additional Drivers dialog informing the user of the regression risks; a link is also included to the specific driver release notes to allow users to make better informed decisions before installing it. Thus, as per the Technical Board guidance, reports of regressions will not necessarily halt the release of the update, especially if the findings can't be independently reproduced for verification. It is allowable for the driver to be SRUed prior to (or without) a corresponding dev release counterpart.
The x-updates PPA includes stable upstream releases of video drivers and associated parts, which can be installed individually or system-wide. This is a semi-official PPA, in that the ubuntu-x team has oversight of the contents of the PPA and accept bug reports about its packages (although at lower priority than regular archive packages), but the package updates are often done by community volunteers.
The xorg-edgers PPA contains packaged snapshots of upstream git trees for the entire X stack. The full PPA should be installed system-wide as per the PPA directions, to ensure all dependencies are properly met. While the ubuntu-x team maintains this PPA, it is intended for testers only and not an official PPA. Bug reports are not accepted (they should be directed to the relevant upstream project instead). No support is provided, and it is NOT recommended that users install this PPA on non-testing systems.