Looking at how the locale.module works now, e.a. every site owner is doing their own translating. Sharing these translations is not a very well supported process. How about extending the locale.module some. One should be able to devide translations in catagories, e.a. this translation was for drupal 4.2.0, for module X v.4.3.0 etc. Then other drupal and module users could download (import) translated module or `drupals` from the main drupal site per language and per module (or also an extra package with all standard modules).
An export button would export stuff, e.a.
export: node.module -> v.4.2.0 -> translated strings -> v1.0
or
export: user.module -> v.4.2.0 -> translated strings -> v1.0
which others can then ..import?
The v1.0 would resemble a translation version.
When you import stuff, you get your specific modules up to date in your languages.