> I've also always wondered why the CPU isn't stuck on the back of the monitor where it can be provided with better airflow.
That would result in increased latency between the CPU and the rest of the system. Put the the motherboard and memory on the laptop's monitor and it would start getting too top-heavy.
I was suspecting something like that, though with the weight of laptops these days, I suspect the top heavy will become less of an issue. I'd guess HD,keyboard,trackpad and ports are the majority of the weight in the lower half.
That would result in increased latency between the CPU and the rest of the system. Put the the motherboard and memory on the laptop's monitor and it would start getting too top-heavy.