[steveklabnik]

One of the benefits, historically, to both languages is that they share a very large chunk of the language in common. It's therefore in their common interest to try and maintain that common subset wherever possible. The goal here (just to be clear, from my outside perspective) isn't to unify the languages, it's to ensure that stuff that's the same stays roughly the same. If the same code produces two different things, based on the language, that's unfortunate. Code that works in one but doesn't compile in the other is totally fine, of course.