I just got a question. 

I use 2 translations on my board and once IPB4 is ready and released will i have to do all the translations again or will it port over my current languages and import them into the IPB 4 forum software? 

Thanks.

Accepts a tip of, since I do translations for 15 years, parts from scratch, are two completely different translations.

Same here... Translations from 3.4.x didn't work for me on 4.0 (sometimes, they broke things - i recommend to uninstall old languagepacks before upgrading to 4.x)

​But 4.0 is worth to redo it from scratch, many improvements to the translationssystem

I'm doing the translation of the Italian version 4, are 95% and are over 5000 phrases, a great job. There is also to say that each version adding new phrases and you must eliminate other and change others, I hope in a final version, otherwise the work will never end.