Besides the obvious advantage of having power players like Oracle, IBM, and Apple behind OpenJDK, there are other interesting observations to be had here. For one, there had been lots of wailing, gnashing of teeth and complaining about Oracle's heavy-handedness. Similarly, there had been complaints about Apple and its policies and a desire for Apple to provide its OSX implementation as open source. In the end, this happily turns out to be unnecessary angst. Henrik discusses this in his post:
This announcement is the result of a discussion between Oracle and Apple that has been going on for some time. I understand that the uncertainty since Apple's widely circulated "deprecation" of Java has been frustrating, but due to the nature of these things we have neither wanted to or been able to communicate before. That is as it is, I'm afraid.I think it's obvious why many of us had concerns about this, but I'm glad that in the end Oracle and Apple were doing what's best for Java.
Another interesting observation or question is what will Google do because or about this? Will Google join the OpenJDK to use in conjunction with Android?
The announcement about Apple joining OpenJDK is huge and positive news for Java developers. I also wonder if some of the many people who talk about Sun as if they could do no wrong and Oracle as if they can do no right will acknowledge that Oracle appears to be doing something with OpenJDK that Sun failed to do: bringing the biggest players in Java together behind a common open source implementation of Java.