The AdoptOpenJDK program is an initiative to get as many Java users as possible to try the OpenJDK 8 preview builds, so that feedback is collected before JDK 8 is officially released. There are many ways to contribute to this program (as explained on the wiki), but the most basic one is to start testing your own project on the Java 8 platform. CloudBees can help you there, as we just made OpenJDK 8 (preview) available on DEV@cloud so that you can configure a build job to check project compatibility. We will upgrade the JDK for all recent preview builds until JDK 8 is final.
With the many open source projects already hosted on DEV@cloud through our FOSS program and the free availability of build resources, we hope this will help the open source community improve JDK 8 quality as it moves toward release.