Off a gamespot article: "Late last year, Nintendo executive Reggie Fils-Aime told CNN/Money correspondent Chris Morris that he expects the Revolution to be "at a lower price point than our competition."
Now, that must presume that the lowest priced competitor is the Core version 360, which is $299. The components in it are significantly cheaper, so Nintendo will be able set a price lower while taking the same percentage to loss. I would be absolutely shocked if it came out over $250.