It's explained in a previous entry: http://www.jroller.com/scolebourne/entry/no_more_java_7 TLDR: He theorized that Sun was planning to avoid claims of standards hypocrisy by never submitting the Java 7 spec for standardization in the first place.

It didn't quite play out that way, but it will be interesting to see what kind of non-reform reform Oracle has planned for the JCP.