Originally Posted by cthulhu
I believe Ubuntu has a "stability before bleeding edge" philosophy, just as Debian, which it is based on. Therefore you are forced to use other repos for bleeding edge stuff.
Ubuntu has a "we don't do major updates during a release cycle"-philosophy, e.g. if the current driver version is 195.*.* at a release (e.g. lucid lynx) ubuntu won't update to anyhting newer than 195.*.* during this release. This also applies to other software such as KDE or Gnome, only minor (security, bugfix) releases are allowed.
Users are free to use ppas (own risk), which are always third party. Other possibilties are sometimes backports (packages for an upcoming release which have been backported to the current) or, not recommended at all, the official packages for a newer release.
Nvidia does, as far as I am informed, not provide any distribution specific packages, neither for ubuntu nor SuSE nor fedora or anything else.