As you know in vm2.0.22 we stumbled again over the language stuff.
I think we should discuss and exactly describe how the languages should be determined. Of course the first idea is "We take the language of the user", but that means that we need a product description in any language.
Atm we can provide with joomla 20 languages, but only fill 5 languages per product. Atm it checks if the selected language is also available as vm language and if it is there it is used. Otherwise it uses the fallback to the first listed language.
To make the perfect, we would need a table refering languages to others,.. for example portugese users would see the shop it self in Portugese, but the products in spainish.
But there is still the problem left, which language to use if you install the shop. Atm I tend to the idea that it should use the main frontend language of joomla.