In it's current state i'm doubting it. The midpath emulator in opendingux is a way to play java games currently. I'm guessing the emulator means that a proper java implementation does not exist in opendingux currently. It's a very good question though. java would certainly open up a ton of possibilites.
edit: i misread your question. you were asking about emulation directly. yes, midpath exists and is installed in the custom firmware.