While we've all been bricking and unbricking, flashing and configuring our N97's Nokia Beta Labs have quietly rolled out a Java Runtime update for the S60 5th edition platforms.
http://betalabs.nokia.com/apps/nokia-java-runtime-20-for-s60
I suggest you read thoroughly the installation instructions. It has to recompile your applets in its second pass and then reboot to fully function. Interrupting it during this process is to be strongly avoided.
I've noticed a bit of improvement in the few Java applets that I've run so far.
I'm going to retry some that didn't run so well or not-at-all before and see how they fair.
Post your comments here.