If it's going to fly. It better be something that knocks your socks off.
What Amiga had going for it was superior Video/Sound capability and hardware accelerated subsystems. And smart designs like seperate cpu/io bus with it's own memory.
And a price that was small enough to be overcome by a generation of college students.
One trend that could be exploited is the open source and going small (asus eee). Make something with complete and open documention like the IBM PC had in the 80s. Make it small like the eee. Use efficient hardware. And low memory and cpu footprint software.
Fit it with a killer price.
Also when I used AmigaOS applications easily crashed the entire system with bad memory access. This won't do. The OS will have to do memory protection, virtual memory (swap), preemptive multitasking etc.