How many letters are there in the Slovak, Czech, Hungarian alphabet. Is it 26 + these extra letters?
Or do they replace other letters?
I think in case of all the mentioned languages it is 26 letters of basic latin + those extra.
For Czech it is 41 letters when combined, and Slovak language got similar number.
Hungarian is a bit different (contains some digraphs and such, which are basically two normal letters next to each other, counting as one letter of alphabet, so i guess it couldbe "cheated" a bit) - essentially it is also 26 + extra.
Personally, i couldn't care less about any other languages, but i am surprised you did not take this into account before and do not already have some kind of unicode support in (as your question implies).
So, maybe you could just add it to your TODO list? (of course somewhere near the very end
...just to keep it on your mind, in order not to do something that would make possible implementation too difficult some day in the future).
EDIT: also, what about all the chinese, japanese, russians, and other ppl using strange languages?
Let's not forget how many of those ppl are there - it could be a relatively cheap change on the programming side of things, and it might help spreading the game to even wider audience, as the OP points out.
I am talking only about the support for different languages, i am not saying you should automatically provide translations for all of them, that could be a significant investment you might want to avoid - and again as OP pointed out, various translations might be done by members of this very community, just give them the option.