I'd like to see this too at some point. The alphabet is relatively easy for Latin-readers to learn which removes what could be a great hurdle in learning a non-Latinized language.

I would love to see modern Greek as an option

The best way to make sure that a course is created on Duolingo is to ask people in your social networks to apply to create it. If a person is fluently bilingual, they can apply at http://incubator.duolingo.com ^_^

I would like to see greek too !

Indeed. I was hoping they'd have it. You can always try LiveMocha but meh.

Modern Greek would be amazing on here! Is there any progress on this happening?