Does dolphin supports dual core cpus? if not, are devolpoers planning to make the emul to support dual core later??(like AMD's X2 or p4 D processor) because it seems only 1 cpus working when dolphin is running.
Now, you asked if they're supported: yes they are. Are both used? Nope. Re-coding an app especially of this complexity to use two CPUs and keep in sync is a huge task.