The PS3 PPU is actually multithreaded, it needs to be seen as two CPUs. And the SPUs are actually more powerful than the CPU, thanks to their 128 registers. So talking about 8 CPUs is factually incorrect, but quite close to the reality.
There is no way your laptop's CPU is more powerful than a Cell. If PC games are better-looking nowadays than their PS3 counterparts, it's because PCs have more memory (the PS3 only has 256MB of RAM) so they are able to store more textures, more complex meshes, and more precomputed data, and because they have better GPUs with more memory (the PS3 only has 256MB of VRAM), allowing to render more textures, run more complex shaders, display more particles, in a higher resolution, with antialiasing etc. But for pure number crunching, the Cell outperforms any laptop CPU I know.
Now in terms of emulation, the Cell is a nightmare. The PPU is not a problem, OS X is the proof that an X86 CPU can run PowerPC binaries efficiently. But for a given SPU program, even if there is a way to do the same task on a PC, you can't simply do the task the PC way: you need to emulate code that was specifically written for the SPUs, taking advantage of the super-fast local memory and 128 vector registers.