Northwest to charge more for prime coach seats

For an extra $15 Northwest pax can buy "prime seats" (exit row seats or aisle seats near the front) in coach... I'm wondering if there will be a discount for seats near the lavs?
On a serious note, what about the safety issue of siting in exit rows?
I can see the commotion at the gate now--Sir I realize you paid for the exit row, but do you really think you can be of much help in the event of an emergency with your leg and arm in casts?
Comments???

Keep'em flying