RasPi support is being added to Aros on a daily basis. $35 mobo anyone? But before you shout for joy, remember that a PPC is about 2x as fast per clock cycle and Intel is about 4x as fast per clock cycle versus an ARM CPU.
Since code density affects the efficiency of the caches, RISC processors have poor performance. My suggestion is wait for the next-generation of 68k compatible FPGA cores. They may not be as fast as PPC native code on PPC but can probably beat some emulators. Likewise ARM CPUs are sloooow per clock cycle.