Hebrew for English speakers!!!! !!!! 1111
תודה רבה, Duolingo!
You know, it wasn't really out of nowhere--the Hebrew team and Israeli/Jewish/Hebrew enthusiast friends have been active for a very, VERY long time promoting the Hebrew language. Years even. Have you seen the weekly Hebrew Time posts? So I think that really it makes sense considering how much people have been advocating toward this, albeit on the DL.
Actually, it's short for 'down-low' like 'keep it on the down-low'. If I'm being honest it was a bad choice of slang, because it's really only an LA-regional thing, and I'm from an hour from there and I only learned it when I spoke to my LA friends! But now it's become part of my speech. Either way, it means that it's a secret, or subtle, or not widely known.
Esperanto, Yiddish and now Hebrew? We just need Ladino and all the major Jewish languages will be represented on duolingo (ok Esperanto isn't a Jewish language but it was created by a Polish Jew and was therefore banned or persecuted in many countries because of it). Also I don't see much need for Ladino yet, since it is mutually intelligible with Spanish, but it would still be cool in the future, or even a Spanish dialect add on for words, spelling and grammar that isn't the same as standard Spanish.
I wonder, since they are both starting at the same time, are both the Yiddish and Hebrew team going to work together a bit because both languages use the same Hebrew alphabet? Maybe brain storm on the best way to teach it to us? Sorry if I'm a bit ignorant about the script, I do know that Hebrew and Yiddish are sematic and Germanic languages but I had heard they use the same alphabet and figure they would have some of the same starting challenges.
If Veneto's http://en.wikipedia.org/wiki/Veneto political aspirations continue to grow, it might be a viable possibility at some time in the distant future.
In the meantime, since Ladino is considered closely related to Romansch (one of the four official languages of Switzerland) http://en.wikipedia.org/wiki/Rhaeto-Romance_languages , that might be slightly more reachable goal to anticipate.
I wasn't able to find any reference to a significant body of native Judeo-Venetian literature, but I would be interested in hearing the famous "Hath not a Jew eyes?" soliloquy interpreted in the language Shylock would have spoken.
Edit: for those unfamiliar with that classic speech from English theatre, here it is performed by Robert DeNiro: http://www.youtube.com/watch?v=th7euZ30wDE and here by Orson Welles: http://www.youtube.com/watch?v=aH2a45plqQc
Here is a book about jude-venetian, "La parlata degli ebrei di Venezia e le parlate giudeo-italiane" (Umberto Fortis, 2006)
Concering 'ladino' it is easy to misinterpret, there do exist two different languages with that name, one is the one you mention, the romansch-related one, not at all related to jewish tongues, but the other one that is called 'ladino' is judeospanish / judeocastellano / sefardic, with origin of Spain and since the expulsion there spoken all around, especially in Anatolia, Nortwestern Africa, and the Balkans, but also in the Carribean and South America.