I remember those days. Not a lot came out of those presentations, though. It was a lot about Java guys having a bit of dynamic language envy, while having to code with Struts and 1.4 Swing all day. A way of getting that hype and with it some new tech to play with into the enterprise by a backdoor. Which is way too hard to do.
Mobile dev being new, even Java developers get to play with more shiny toys. For good or ill...
For my day job, we use Groovy for our Spring Boot app. I love it.
I've also done a lot of Grails development, which I enjoyed also.