Please see the comment above: even though the main compiler is in maintenance and stabilization mode, innovation has happened in Scala in the form of independent projects, driven by people in Martin Odersky's lab.

The former developers on Groovy are spending most of their time on their day jobs these days and they don't seem that interested in Groovy any more, except when they're promoting the existing version at conferences (and they tend to talk more about the fabricated number of downloads there anyway). Despite the grandiose plans of possibly improving Groovy with a proper meta-object protocol at some point in the distant future, Groovy has been in decline for a couple of years now and with less and less people using it, and those that do use it only using it for 30-liner test or build scripts, it's probably going to stay this way.

Such a missed opportunity.

I think the only reason Groovy is still around today is Gradle. Once Gradle starts declining, Groovy will probably disappear along with it.

This is what we call FUD.