Good idea, but it looks to me like an easy way to find out what a shotgun smells like.
Couple downfalls with it.
Pillows love to push up against the headboard.
If someone is in your room and you need that quick of a recovery, odds are your wife is going to sit up instantly and you'll rack her in the back of the head as you sweep.
What's she going to brace her hand against so her face doesn't hit the headboard.