JaicraB has posted on his blog, releasing his OtherOS base exploit and source code.
To quote form his blog:
Here you have a minimum base to build the otheros.bld. The functions are described.
Call table incorporates LV1 and ASM functions. This ready to assemble the mechanism of the exploit. I hope this helps those concerned who did not know where to start. It has been compiled with the toolchain pdaXrom.
Source Code for Base Exploit:http://www.megaupload.com/?d=IY7QBX7Z