The leJOS team has released a new beta version of leJOS NXJ, the Java platform for the NXT.
leJOS NXJ 0.4 beta brings along new features like
"NXT to NXT Bluetooth comms, a comms proxy to talk via sockets to the outside world, greatly improved MIDP LCD UI and graphics, primitive playing of wav sound samples, a multi-level menu, and lots of other enhancements"So if you are interested to implement your NXT programs with Java, give it a try!