I think that the DNN-Connect module has the best option atm.
I have been using it to collect language packs, update with new versions, etc. Yep, it needs some love. The problem you mention could be covered in code.
I the past, you had auto translate, using Google Translate V1. That would speed up things a lot. The auto translate was never updated to GT V2.
But what I am really waiting for it the possibility to edit and update the core none en-US LP's. Why are those not in the DNNPlatform repo?