There is rumor that Google is considering making Swift a “first class” language for Android. I don’t know what “first class” would mean in the context of Android, but I would assume that it means that Swift could be used in the standard Android tool chain in the same way that Java is now. I could see how this could be a big deal and how it might not be.
For the change to happen, all the Android API’s would need to be exposed as Swift API’s and then the Swift source code would need to be compiled to Android bytecode. This seems rather trivial for the big brains at Google. So I don’t really see this as any kind of technical challenge. But how do you introduce and migrate this into the developer’s tool chain when 60% of your userbase uses an OS version more than 2 years old. So if developers aren’t likely to switch to your new tools, why develop them and what is the calculus for how likely and how many switchers are needed to make the switch make sense?
Moving to Swift might cause me to re-evaluate development for Android. The main reason I don’t is that I do Java at work and have no desire to see more of that style of coding. However, Swift for Android isn’t likely to make development easier as Cocoa Touch and the other frameworks that make up the substantive parts of app development aren’t part of the open source project. I’d get to use the language, which is one level of expertise, but the libraries would be completely foreign and incompatible.