Netbeans.org tells us Java's move to open sourcedness has started:

The initial pieces of Sun's Java Development Kit (JDK) have been open-sourced and are now available for you to download, browse, and build from java.net.

Once it's "done-as-in-done," I wonder if any alternative form of Java will cause versioning headaches (I doubt it in the short run, certainly, but there could be a Camino:Mozilla::[New JDK]:Sun's JDK, etc).

Most importantly, though, I believe this pretty much secures Java's future even if Sun, for some reason, gives up or goes under. You should feel much safer about investments in Java code or learning Java programming skills with this announcement now that its life isn't bound directly to a commercial corporation. Java can go places it couldn't before.

More on the Open JDK is here. In case you're wondering, yes, it's using the v2 GPL.