What's really going with the Oracle/IBM agreement for OpenJDK and future Java development?

The news yesterday is that IBM ditched Apache Harmony (all but killing it) and has backed Oracle and the OpenJDK project, putting its development time and resources there. In my opinion, this move helps to ensure that Oracle will get the speedy approvals it needs to get the Java SE 7 and Java SE 8 JSRs approved and out the door in its desired timeframes.

What does IBM get out of it? After all, they're placing developers and other resources on the OpenJDK project and that costs real money with a commitment over time. I'm not entirely sure, but I assume they'll have more control over its future, and some more leverage in getting its own versions of the Java VM (i.e. IBM's J9) approved as an officially licensed VM. IBM had none of this, and no control over Java, once Sun had released it as open source. This new agreement could potentially change that.

For now, it looks like the first victim will be Apache's Harmony project, which has been moving along only with IBM's support for years now. Although Java's source code is open source, Sun never released the full Java compatibility test kit (JCK) to the community, and this had been a point of dispute between Sun and Apache for quite some time. Without passing the JCK, you cannot call your software "Java" or Java compatible in any way, because you can't prove to yourself and others that it implements the Java language specification correctly and completely.

From what I've been seeing and hearing, most people look at this as good for Java and the community for the most part. My only question is, what made this deal so sweet that IBM, the target of much of Oracle's propaganda and competitive press over the past year, has agreed to jump in and help Oracle? Time will tell.

Happy coding!
-EJB