I think the project is really needed, but I'm not sure it's quite ready yet. The OpenJDK 10 build shows 25 November 2017 as it's build date and is Linux and macOS only.
In my case the certification probably won't matter, we've been running with OpenJDK from debian for a long time without problems, but I'm curious to test the OpenJDK builds that use OpenJ9 to see if it can outperform Hotspot on some workloads.