I disagree. Right now it doesn't seem like a lot of things aren't possible in swift unless there is a LOT of undocumented API.
Dynamic method compilation that you would need to make an equivalent of DynamicProxy just doesn't seem possible. What's funny is that the #1 thing I would state is not possible in Swift is Core Data.
While it is clearly still somewhat limited, it does seem like there is potential for it to evolve into a really robust reflection API.