Yah I think someone found an exploit using the OTHERos feature, to run unsigned software.
They're panicking and removing the option. That being said I tried it out once, but found it pretty useless. They block access to the GPU so there's not much you can do with it. Install some old game emulators and what not. I wanted to try to use it as a media player, but the lack of GPU access made that impossible to do HD on it.
Now I need to reformat my HD so I can get access to the 10ish gigs the system reserves for OtherOS. I'm guessing the update will make the option dissapear but no solution to reclaim the space.