What is in your current system including monitor rezs and power supply brand/model? Does your mobo support SLI or crossfire?
My PC Info: HP Pavilion HPE h8-1270ea Desktop PC Intel Core i7-2600 Processor, Genuine Windows 7 Home Premium 64 Bit, Memory: 8GB, Hard drive: 2TB, Optical drive: Blu-ray Reader, DVD Writer, Graphics: Nvidia GeForce GT 545
Can you please provide more info from the label on the 460 watt power supply? Specifically, the number of amps for the 12 volt.
depending on your power supply, best wait a few weeks for the Gtx 660ti, as world of warcraft in general prefers running on Nvidia cards. it should be low enough so that if necessary, you can buy a new psu and still be under 400$