i want chinese lessons
I think that the reason that they are starting off with Western languages is that it is easier to translate from English to Spanish or French then it is to do the same with Chinese or Japanese. Nevertheless It would be great if Duolingo supports Chinese and Japanese. Chinese will probably be built before Japanese because of the many difficulties with Japanese (new alphabet and very different grammar structure).
I'd love to see Mandarin on Duolingo! I'm working on a project which is creating Mandarin resources and teaching methodologies for school kids, but my role is simply a production/design one. I'd love something like Duolingo for Mandarin to keep me on my toes while I work on these kits. ;-)