By accident, a bug in the Icetea-openjdk plugin, forced my wife to boot up my Fedora 13 Alpha install and try to run Ameritrade's Command Center on it. Command Center always needed Sun's Java jre to be installed, Openjdk was never able to handle it. But surprise, without Sun's Java being installed, I have Command Center running on Fedora 13. Kudo's to the Openjdk devs, I was just about ready to start testing the new version of Sun's Java with Firefox 3.6, which contains a different plugin which has to be linked to, now I don't have to.
I guess it's worth trying Open Source alternatives with each new release, There are many surprises hiding under the hood.