I was just about to let you know that yes, all the Yamaha's have pitch correction with their vocal harmony keyboards but you all just beat me to it.
Also, for those of you who own the G70 Roland or if you can get to a store that has one on display (probably only mine!) on the west coast, I would suggest you enter the demo mode and go to vocal harmony and select the button labeled "vocal harmonist" and then select "auto pitch correction". You will begin to hear the song Amazing Grace and if you plug in a mic you can sing and the G70 vocal harmonizer will put you perfectly in tune no matter what you say or sing. It is the same as on the Discover 5 keyboard but the Discover 5 had no arranger and no sequencer, it only played standard midi files.