Until we have (practically) limitless processing power all computer graphics (realtime or pre-rendered) will not be able to achieve photorealism ...
By the end of 2010, a PC using two or three graphics cards hooked up using SLi or Crossfire will probably be close to the quality of pre-rendered movies of 2000 to 2005 at high resolutions (obviously using rasterization); in 2015 a bleeding edge PC will probably be close to the quality of pre-rendered movies of 2005 to 2010 at high resolutions using ray-tracing.







