This is an interesting suggestion. However, if you want to become a better chess player it is always good to try to train yourself to play the same way no matter what the rating of the opponent is. You should not play intentionally sharp, risky, second best moves against lower rateds hoping for a mistake or play too conservative and passive hoping to draw against a higher rated. Best is to try to play the same way no matter the rating of the opponent.
I know, from experience this thinking has really helped me in my chess play.
Whenever you're playing with a player of higher rating than you, from the start you subconsciously 'know' that he has an edge over you, this psychological factor may contribute to you playing bad(or maybe even good) as a result of being overcautious. It would be nice to have an option to hide your opponent's rating, perhaps, while specifying the seek parameters.
btw, I got this idea after reading this article about an unsolvable math problem: http://www.snopes.com/college/homework/unsolvable.asp
Edit: 'Hide opponent's rating' would have been a more appropriate heading.