1. Supported Languages
There are currently 11 language files included in the current stable version 1.3.9-pl1: Dutch (Nederlands), English, French (Fran?ais), German (Deutsch), Italian (Italiano), Latvian (Latvie?u), Polish (Polski), Portugues (Portugu?s), Russian (Русский), Spanish (Espa?ol) and Vietnamese (Tiếng Việt).
Two web sites with other languages have been spotted: Arabic and Norwegian. Efforts are underway to include them into the next stable release.
2. Work in progress
I am working at a translation into Latin. I am unaware of any other efforts to translate the phpMyFAQ. There had been a discussion on someone to translate it into Japanese (日本語) . Please tell me if anyone has started other translations. Month ago
3. Most wanted languages
According to statistics, the most commonly spoken languages are as following (I highlighted the ones we yet do support):
1 Chinese 957,132,000
2 English472,000,000
3 Spanish352,000,000
4 Russian295,000,000
5 French269,572,000
6 Portuguese198,000,000
7 Arabic195,950,000
8 Bengali 189,000,000
9 Hindi/Urdu 182,000,000
10 Japanese 133,000,000
11 German 107,000,000
Those numbers do not represent the language majorities in the internet world. I guess that the statistics from the great wikipedia project can be taken to have a quick look on how many languages are strong on the internet (the error factor will be incredible high!):
number of articles on December 6 2003:
1 English 368,000 – X
2 German 181,000 -X
3 French 40,000 – X
4 Dutch 21,000 – X
5 Polish 20,000 – X
6 Spanish 18,000 – X
7 Swedish 17,000
8 Japanese 16,000
9 Chinese 14,000
10 Esperanto 13,000
Of course, there are much more efficient and more reliable data sources on the internet:
http://www.glreach.com/globstats/
http://directory.google.com/Top/Computers/Internet/Statistics_and_Demographics/
However, I tend to stay outside the “serious only”-room. 
Have fun.