My dell will be on sale soon and will be replaced by a new powermac. which should I get a 933mhz or the new dual 867mhz?? The new changes to the new powermacs are big enought to pay more for it? 933mhz has the superdrive, same graphics card with more ram same Hard drive 867mhz dual! DDR Ram, combo drive, jaguar any thoughts would help.