Having a sophisticated community of localisers is a mixed blessing for software developers. When software is to be localised, they expect the constructs they need to properly localise for their language. Particularly the support for plurals is considered to be essential.
The way it works at translatewiki.net is, that when a new application is accepted for localisation, it is made clear what functionality needs work. Top of the list is the ability to import and export. As a consequence the list of supported formats has grown considerably.
Working together in translatewiki.net proves to be mutually beneficial; new applications like OpenStreetMap brings new people even languages to translatewiki.net and the existing community has adopted OpenStreetMap enthusiastically. Most importantly, the usability of the software is enhanced because not only are localisations in many languages added, the English texts also gain plural support and becomes better understood.