So is now the right time for quad-core CPUs? Hell yes it is. It was the right time for quad-core months ago. It's the right time for six or eight-core CPUs. You could give me 16 cores and I would ask where the 20-core chips are. More cores are faster, and faster is better, because it enables richer, easier-to-use, more fun software. Bring on the many-core CPUs, heavily multitasking OS environments, and multithreaded software. I'm ready for the parallel processing universe.
Source:Do We Really Need Quad Core?