The reasons for these changes are:
- Giving you control over the word order with placeholders
- Proper plural forms
- Proofreading of the English strings
- Improved formatting of campaign scenario texts
The campaign scenarios will be seriously broken, so I recommend that you work with both the old and the new version of the file side by side - some strings have been split into multiple strings. I will help with fixing these in Western European languages. I don't read the other languages well enough to help there though.
I will grab an archive of all translations before the change so they won't be lost, but you will also be able to get your translations from the locale folder in your Wideland installation. You will need Virtaal or Poedit to open those, since they are in binary format.
I will post again in this thread once the chages have gone through.
ETA: For list of terminology changes, click here.
ETA: For a guide on recovering old translations, click here.