Hi Joe, Magnus, Andrew, GerardM, Jane, Daniel and Wikidatans, 

Since "Language fallback is not a luxury like it is for British English, it is essential for all the smaller languages. It is what prevents it from being editable / usable" (per GerardM), and in terms of Reasonator, statements, and careful design (DanielK), what are current Wikidata processes to plan eventually for all 7,106 living languages (plus even dead and invented languages) in the world per "Ethnologue: Languages of the World, Seventeenth edition" (http://www.ethnologue.com/statistics/size), as people add them, and use, for example, the ISO coding system (or similar) for this, to anticipate not yet added languages, and especially for 'smaller' languages that GerardM mentions?

In terms of British English (en-gb) and English (en) distinction, why not just code English in Wikidata as "ISO 639-3eng" per http://www.ethnologue.com/language/eng as part of a careful design for all languages, and then build out for smaller languages? (CC wiki WUaS is planning wiki schools in all 7,106 languages, plus dead and invented languages). 

It seems that using or keying in on the ISO system, or a similar one, would allow for remarkable extensibility and careful design of Wikidata, as well as fallback for other languages such as Hindi, Odia or Malayalam.