QNX for Mac?
MacOS Rumors posted this heads-up on a comment by Dan Dodge regarding a PowerPC/iMac port of QNX.
Apparently, QNX is already running on an iMac to some degree, but with no USB support and "Give us 2 months and some spare cycles to get it on the iMAC and we will see what the demand for QNX on this machine is."
Another interesting comment is " What we would really love is to partner with a hardware OEM to bundle QNX on their PPC machine."
Apple? I don't think they'd be interested, but they're the biggest player.
What is QNX? and QNX's site.