Hmm... which page is canonical for e.g. search engines. I have an English language source page and an English language subpage with /en. Well this does not just apply to search engines: Which English language page is supposed to be served to users?
Topic on Help talk:Extension:Translate
Currently, the /en (or whatever is the source language) is only there to be used for transclusions (Template:TNT for example).
Well all languages should be treated equally so the /language code pages are the once to be served to the audience. Still not sure what search engines like Google make of it and what this means for sitemaps
Ah, did not see Nike's post.