WRT to Java support: Since it doesn't appear to generate poms or publish to maven repositories it doesn't seem very useful on the open source part of things. It seems explicitly for generating internal, proprietary software from a monolithic source tree. I would have much rather seen the incremental compiler and jar generator integrated to maven than replacing the entire build system.
Actually Maven 3.3 was released recently which has a smart builder for building separate parts in parallel, and using Takari plugins you can use the Eclipse complier which is parallelising in itself. See http://takari.io for more details.
