One of the main advantages of optical processing is the heat produced/energy requirements, and quantum computing isn't nearly as far away as you think - keep up to date with the physics news
As for multicore processors, lots of tasks can be parallelized such as audio and video processing or physics processing. "Beyond hd" video is already available in Japan, takes a lot of processing to handle even "hd" video. Fortunately the massively parallel gpus are well suited to the video task.
I'm happy with my dual core for now but as a heavy multi-tasker and virtual machine user, cores and ram are more useful than most people think.
AMD AthlonX2 5000 black edition @2.8ghz, 2gb pc5400, AMD/ATi hd3850, creative xfi music, 24" hp widescreen 1920x1200, ECS KA3 MVP mobo