If you had told me before WWDC 2014 that Apple would introduce a new programming language, I would sadly shake my head. So many programming languages are created without leveraging any of the lessons of languages that have been around for decades. My general attitude is that there is little reason to create a new language instead of building off an existing one.
So far, however, Swift has impressed me. I can’t really find much to complain about.†
You could argue that in many ways Swift does build off Objective-C rather than being a new language, but that argument sells Swift short. This is a very impressive design.
†OK...here’s a...observation: It seems like having some kind of cycle-detection to augment ARC ought to be there.