What do you want for next year on Duolingo???
More stories, as well as longer and more advanced stories. Consider works of literature no longer governed by copyright laws.
More opportunity to learn cooperatively with other users.--a more meaningful way of being a "friend" or following.
Intermediate and advanced courses (or at least "branches")
More audio exercises that require translation into the target language
Multi-sentence exercises, both for more of a challenge and greater context
For new users: Email verification to complete registration, and a mandatory video tutorial on using the courses and the forum.
For existing users: Speaking exercises for the Japanese, Korean, and Chinese course, advanced tree branches (branch = multiple skills) to buy from the Lingot Shop, fixing the forum bugs, and adding new search features (like searching posts on or between specific dates).
For duolingo: New means for monetization (Like a Duolingo X Language Test for languages other than English).
What I want? Don't get me started...
Courses I want: Finnish (duh) Corsican, Tamil, Latin, ASL, Zulu, Catalan, Mohawk, Thai, Chinese with Traditional characters, Japanese and Chinese for Spanish.
Courses I want released: Indonesian, Haitian Creole, Hindi, Yiddish, all for English speakers, and Russian for Spanish.
Features: Return of Activity, Progress quiz, and Immersion, a tab where you can find native speakers of your target language to practice with, Stories and podcasts in all languages, words tab for all languages, an audio button in the words tab, duo breakdances whenever you complete a lesson*, bots for all languages and on PC, more language TTS for Tinycards, and more stuff I can't remember at the moment.
Other stuff: All forum bugs fixed, forum rewrite complete, NOTIFICATION BELL FIXED, more bonus skills, oh, and I want Staff to hold a raffle for a Duo plushie.
Not as much ASL, but more Morse code. ASL will be hard to teach on Duolingo. You also forgot Hindi for English. Personally, I hope that the English for Tamil, Telugu, and Bengali courses come out so a switch from those languages to English afterwards will be easy.
Incubator-wise, I say Icelandic, Croatian, Thai, and obviously Finnish. Slovak, Slovene, and Catalan would also be nice assets to the incubator. Portuguese for German and Polish for Spanish would be amazing, too.
I think they should add a "Slang" course to the Lingot store. There should also be better sentences in courses.
Riddance of text-to-speech. I want real voice.
Baltic, Icelandic, Scots, Gaelic, Ancient Greek, Latin, Middle Old English.
Completed audio for current courses. Esperanto seems to have some single words missing from audio (I mean, being unable to click on the word and get the audio for just that word; this sometimes makes it difficult to get a good read on how the word is sounded out), and Swahili had a lot of stuff missing last I checked. Hebrew kind of gave me a headache too, but I never got far in that course.
Notes and tips in the app.
Some more bonus skills would be nice, but that's up to the course creators, who I'm sure are busy enough.
For new languages...still would like Latin, and am looking forward to Arabic and Klingon, but I'm pretty much good for now.