Today is NOT the day you will start learning other languages.
Just to clarify - Incubator starts today only with the possibility of adding new languages to translate to English, German, French etc., and not from them to new languages.
So that means you will now have the option of adding your language (or for example, mine - Croatian) and make lessons to teach Croatian people to speak Italian. Not the other way around.
The Incubator should fully start by the end of the year when there will finally be a possibility of learning other languages beside the ones already on the site.
Please read the official notice once more: http://www.duolingo.com/comment/868354
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There are a couple of differences worth pointing out:
The sound will be in english not in croatian, which removes a significant portion of the lesson's objective.
The dictionary hints will not help you with conjugations and cases of the croatian words, they are going to be focused in the english words cases and conjugations.
This is based on my comparison from the French to English and the English to French Courses. There is also a comment from one of the duo developers that finished the Spanish to English tree, and the experience was summed up as "a hard spanish course".
Thank you for the clarification. I had thought that new languages would be added today. I checked out the incubator, and you're right. For now you can only apply to add new languages so that learning the ones DL already has can be possible for more people. I'm still excited to see the options added, and see the DL community grow bigger :)
According to the plan, courses from english to other languages (i mean other than the existing five sp. ge. it. fr. po.) will be permitted in the incubator sometime towards the end of the year. It will take a minimum of a month or two for the course to be developed... so my guess is not before January, but it really depends on the number and motivation of the volunteers.
Swedish has been added, but for Swedish - default DL languages. I guess you could try that out and start picking up some Swedish while you wait for the English-Swedish tree to be built. Keep checking the incubator for Norwegian. It could be any second that some user adds it.