This is the question I got at many events where I presented about localize.drupal.org. We've just rolled out support for suggestion exports for translators about a month ago to make quality control and management easier, but that does not help people much who are just looking to download what's available.
I've also announced about three months ago that translation downloads were becoming stable and continually generated in a nice pace. However, the usability of those downloads left a lot to be desired. When looking at project pages on the site, you were shown a bland list of links to major Drupal versions the project was compatible with which all led to a long list of filenames on an FTP browser frontend. Also, some files being months old looked shocking given I've told you the downloads are now stable and up to date.
Well, as of yesterday, some nice big green buttons landed on several areas of localize.drupal.org which all lead to a new downloads center. If you are on the front page, or a language page, you get to the initial download page which shows Drupal core translation downloads. Project pages however prefill the project selection for you appropriately, so you get to go to the downloads respective for the project. Drupal.org project links were also updated to point to these paths.
We actually have some pretty good data about these translation files that was not available on the plain FTP browser. While some files might be as old as three or even five months, we check the translations for updates and sometimes conclude we don't need to generate new files. Unfortunately some translation teams are not (yet) too active, so it can easily happen that months old files are the most up to date possible. So when on the download page, you can hover over the download links and get some additional data like file size, file date and the last up-to date check time.
Finally, while this was about giving more visibility to downloads, we really love those, who actually contribute. So when you visit the download page for a project, the contribution form will be prefilled with the project, letting you to jump to the project's page on localize.drupal.org directly, or even hop to the translation interface if you also select a language. Contribute and feel the Drupal love!
Ps. Usability feedback on the process is more then welcome. While I think we have far better then what we had before, it can definitely do with some improvements. Also, do not forget to check out the Localization update module to automate downloads, so you don't need to do it manually. A huge timesaver!