Swedish Word List
Will we have one in the future? I would really like to keep track of my vocabulary, not only the words I know, but also the quantity of words I know.
Most courses do not have a word list when they first enter the Beta phase. I am sure there will be one once it is fully released.
It depends on a lot of factors. I think you cannot tell how long it might take. You can get a rough idea, though, by going to the 'Add a new course' menu and select the course in question. It will show a progress bar.
In general, the word list feature in itself is quite new, even for the long established courses like Spanish and French.
Personally, I am not a big fan of the word lists myself because they basically show the words from the tooltip in a rather unreflected manner (entirely context). There are probably better word lists on the internet. For example, there is a list of the 1000 most used words in Swedish on 101languages.net (but no context either): http://www.101languages.net/swedish/most-common-swedish-words/
Before the Words tab was introduced for the non-beta languages, I used this to download my Word list as an Excel doc: http://www.reddit.com/r/duolingo/comments/2el32h/get_your_duolingo_learned_word_list/
It doesn't give translations though.