This was asked only 2 or 3 days ago. The basic answer is no. The iMac uses laptop CPUs. Intel will not be producing a quad-core laptop CPU till next year at the very earliest. So unless Apple change their current iMac idea (basically make it much larger) you'll just have to wait. Also not that 2xDual core is also not possible: laptop and standard desktop Intel CPUs cannot be run in dual or higher configurations.