Happily, the two co-exist well, and increasingly so. Where one is a better choice for a particular job, you have it. It's just that you now have two tools to choose from.
Hearing one of the core engineers from the LLVM compiler team speak at some length about their aims and approach to Swift, it was cleat that they had reflected long and hard on the approaches of many other languages. This engineer had very informed and nuanced views on the strengths and weaknesses of pretty much any other language you asked about. I'm sure Scala was on this list, also "Objective-C, Rust, Haskell, Ruby, Python, C#, CLU, and far too many others to list" — http://www.nondot.org/sabre/
I'm not sure, I've had great fun learning it, and writing it is usually really nice. Sure, there have been pains along the way, but the Apple engineers are doing an amazing job with evolving Swift, intelligently, and very quickly. It is the future, and for many developers I know, it is already part of the present.