At J1. Rich Green just announced option #1 of my three guesses on the messaging around the JCK.

I was wrong. The description is from here :

Sun is going to make it easy to certify the compatibility of implementations based on OpenJDK code by granting access to the Java SE TCKs under a special license, and that in turn will help safeguard the "Write Once, Run Anywhere" compatibility promise for everyone. The details are still being worked out, but we're committed to compatibility for Java technology as free software.

Good for OpenJDK, but I don't really know what this means. Since OpenJDK isn't actually Java SE 6, it's a future version of Java (like SE 7), I suppose we aren't going to see it for a while.