What Louie says is absolutely true, and in my opinion, there is another point coming with this generation which makes the graphics even less important.
I think graphics have become good enough with the sixth generation for most of the consumers. Back in the fifth generation, the graphics really showed that they need an improvement and sometimes the gameplay was handicapped because of the graphics as well. but with the ps2, the gc and the xbox graphics have come to a point were the average consumer is happy with it. i mean, many people say that the graphic of wii sports look crappy, but no average consumer will notice.
i recently talked with a 14-year old boy who plans to buy a x360. i asked him why he wants it, and he answered because of its beautiful graphics. i asked him then why he don't want to buy a ps3 because it has better graphics, but he did not accept that point and said that ps3-graphics are even worse than xbox. he was not joking, he really meant it, and this proves my point. he has been told that x360 has great graphics, but he can't distinguish between xbox, x360 and ps3 graphics anymore because they all look good to him.