isaac: I don't think so. The java library is an overengineered beast and I won't say that it is simple and expressive. This is a side effect of it being a library for an "enterprise" language like java.
The scripting attitude is to ignore details and have something working even if it's not 'perfect', while the java lib pushes the "do it the exact way, then bother about pleasure of use" mood.
Anyway I have to specify that #1 and #2 are provided from many static languages but a static inference able to encompass the expressivity of python/ruby/whatever is yet to come. I bet it is possible, just not yet done.
i.e I'm not sure but IIRC in nice you still had to specify an ad hoc interface explicitly, or can this be inferred automagically?
I'm sorry I don't know Scala enough to comment on it. I was just confused from seing it has traits+mixins :)