If gamecube as hardware finished in 2000,has something like 10.4Gflops powerprocessing (cpu powerpc G3/ 750cxe/486Mhz + Gpu flipper162MHz/ati sub radeon 1 model year 2000 ) and wii is a "gamecube turbo" have early 15/20Gflops overall ...a ps3 with cell with 188Gflops whithout counting with RSX can sustain/processing (25.1Gflops *7 + Powerpcengine/970like/PPU) with very good homebrew, sdk or VMM (virtual manager machine) maybe have much power to emulate with good level.
Rule of thumb i believe is something like you need seven times the original consoles processing power to emulate it, but of course thats just a rough guide. Taking a look at the lack of a decent ds emulator on the pc leads me to believe that even if the power is technically there, it will definitely no be as simple as covering the cpu power.
An emulator that is programed by sony and built into the firmware of the console is very different to a homebrew community made emulator. Dont expect last gen emulators ala xbox, ps2 let alone wii for a good while. Ask again later on in the consoles lifetime and maybe you wil get a different answer.