Unfortunately, it's highly unlikely it will ever work.
I've scrutinized the applet file it's using. It's in a signed 430k JAR file and AFAIK uses standard Java. This alone seems to make it impossible to use this applet in most (if not all) PPC JVM's (because most of them are Personal Java compliant only).
Unfortunately, the server isn't using SHOUTcast, RealONE or WM-compatible streaming, so, you can't use 'standardized' Pocket PC streaming clients (of which, incidentally, I've written a large-scale review in Hungarian at http://menneisyys.freeweb.hu/streaming
I'm continuing to scrutinize the client (I've already disassembled it), but, as has already been said, don't expect much. It's quite a task even for a seasoned Java veteran like me.