why is kotlin picking up so much hype is it actually completely stable now? Would it be better to develop android apps in kotlin rather than Java for my next app? Is java going to become obsolete/deprecated for android?

I'm working with Kotlin because Java is so lumpy and everything takes three other instance in their constructor.
The conjuring thing about Kotlin is you can convert it to Java source if you want to bail. Well, not the Anko bits, I suppose.