ive had 1.4.2_04 working on FreeBSD the day it was released
All you have to do is install the linux emulation layer and the java programs run FASTER on freebsd than on linux (higher FPS)*.
Having said that, i didn't know if LWJGL would work on it and never tested it on there because I didn't know of LWJGL back then.
Unfortunetly, my bios has gone byebye and I need a new pc to install freebsd on inorder to try LWJGL on. As soon as I do (which will take some time, skint at the moment) il post here to tell you the news.
DP
*Tested on FreeBSD 5.1. 5.2 is out now tho.