It might be for the best. I heard that the VMWare people are a bit scuzzy and unethical, such as slapping legal threats on authors to take over their github projects. Of course that was from what I thought was a drama queen ex-groovy committer, but now he looks much more sane.
Pivotal is trying to push vert.x now, which I think is a node.js for JVM type of thing.
Since they never did make an awesome configure-spring-with-groovy conversion, I guess this won't be too painful of a split.
Groovy was the #1 JVM language besides Java for quite a while, I think it still is despite Clojure/Scala hype. It was before pivotal took it on, and it probably will be fine.
It's feature set is actually fairly stable. It doesn't need to do Java lambdas, since it has its own, so no major Java cross compatibilities to port from Java8.
I was disappointed that Spring decided to move away from the groovy config option. I thought of all the different configuration options that one looked the most elegant. I really dislike the current "Java" config fad they are going through. It looks like Java, but it's not really Java, it's a DSL for Spring configuration.
Gradle is heaven for anyone who's ever had to work with Ant in earnest. The programming language is actually a language, not a horrifying accidentally-Turing-complete DSL!