Currently GOG offers Original War in English. However, I know that the game exists in multiple languages - at least Polish and Czech. It might be interesting to have the game available in these languages....
I wouldn't mind paying an extra euro or something for access to the various language packs. Not sure if that can be arranged though...

You can set the game to another language through the OW launcher (it should be called that), but you can set only subtitles. The audio will be only in English.
However I'd like to have the game with another dubbing (I have the Czech version and IMO the quotes are far superior to those in English).

Exactly my point :)
(we could also try poking Stucuk to modify OW so that it could switch between various speech packs if they're available... however that would be a pretty complex task)

Good idea, however at first he should get all the possible dubbings, then work on it and finally notice the GOG staff, they could put it as a optional download.

That would be 680MB roughly for each language and would be the same as copying the data2.owp as well as the Disk2 folder (From a game thats been patched's original war directory rather than actualy from a Disk2)