Benissimo! Excited to say that Italian is coming to Duolingo next Tuesday :)
Right now, they are just doing Romantic and Germanic languages, because they have experts in those areas. Since Arabic is not in the Romantic or Germanic language group, they will have to hire another staff member for it, which would put this off for a while (they are hiring for a Chinese master right now at http://duolingo.com/#/jobs, and they have no due date on Chinese). So, in order to offer Arabic, they will have to hire an Arabic master, which will take a while, and then it will be a few more months before they have Arabic (and they don't even have a position for Arabic master on their jobs board).
Latin is not dead, it lingers in many of our modern-day languages. Just because it's not spoken as an official language anywhere today doesn't make it an invalid language to learn. I'm proud to say that I'm studying Latin, and it helps me in understanding modern-day Romance languages (which are among the most popular). Sure, Latin isn't VITAL, but that doesn't make it invalid.
I saw on one of the news releases that Italian and Mandarin Chinese were next on the list. I did wonder if Mandarin would use Pinyin or use actually character inputs. If they used characters I also wondered if they would use Simplified or Traditionally characters. Possibly a choice between the two? Exciting stuff!
My guess is that the Chinese characters would be accompanied by their pinyin pronunciation. Instead of paying money for the product, we translate text, so unless there are pages of pinyin text out there waiting to be translated, I don't see why it would be commercially viable for them to offer just pinyin.
No, it's extremely easy. Within a month you should have a really good grasp on the grammar. After that, it's all about building your vocabulary. That isn't really hard since most of the words have Latin roots. Like everything though, you have to put in the effort. You should give it a try. :)
I think they should NOT add any other languages to be honest. They should just master their method and technology for the current languages that they have right now. Hell, Portuguese is still in Beta. They have their hands full, I'm sure! Gracias e obrigado Duolingo. Eu te amo ;)
LeviLingo, I agree with that. Diving into Chinese or Japanese is a huge challenge. Both, with learning design and technologically. Learning design: An Asian language is not just another language. it is ANOTHER language. Completely different. The approach as Duolingo does it with romance languages might be unhelpful when learning Chinese. Technological: Getting all the character support in the computer systems can be a major hassle. So I think you are right with suggesting, Duolingo should improve the learning level and experience of the languages they offer now. Keep ahead of the competition.