Is there anything special about OS4, Amiga ONE, Pegasos or what else there is currently out there? I guess my question is also, did Amiga die when Commodore turned the key back in the 90's.
Yes, it is now the only PPC desktop computer.
Depends on how you define Amiga. The AGA machines ended with Commodore. The OS saw abit more life and in fact branched out. It's emulated, copied, open source, and offical development continues.