I think you still have to ship it in a separate tree / binary, but I'm not sure. I don't think the exception means you can put my GPL function in your proprietary code and call it as long as you reveal the changes to my function. But I'm willing to settle for "who knows, really" :)

I worked a bit on Classpath but that was a long time ago. There are like, lots and lots of emails + irc logs to dig up about that little exception and what it means. Not having things tested in court is a problem, and the lack of funding for FSF lawyers is another.