The English Wikipedia is fortunate in that all the MediaWiki software is written in English. The other 259+ Wikipedias have to have their user interface translated in order to understand what the software asks from their readers and editors. This localisation effort is largely done at translatewiki.net. Practically every day the translatewiki.net staff commit the localisations of the software to SVN and these localisations became available when the MediaWiki software was updated. Such updates are not scheduled, but there were months when translators had to wait before seeing the benefit of their labour.
After several false starts, Brion has activated the LocalisationUpdate extension on the Wikimedia projects. This extension will reduce the time people have to wait considerably. It is unlikely that it will exceed three days. As a consequence it is now much more attractive to localise messages.
One of the beneficiaries of the new software is the Usability Initiative. The "Beta feedback" indicated that many people on the "other" Wikipedias tried the software but reverted back to the standard interface. Research showed that this was mainly due to a lack of localisation. When the delivery of messages is happening on a daily basis, it becomes much easier to learn if the problems are due to problems with the software or problems with the localisation.
Statistics indicate a relation between the quality of the localisation and the number of articles. When it is easier and more effective to localise the MediaWiki software at translatewiki.net, we expect that the quality and quantity of the localisations will improve. This in turn will stimulate our readers to become editors and with improved usability because of localisation and functionality we expect an effect on articles in all our projects.