I sleep with my wife, and she has no complaints about the light on the KP2. Unfortunately, there is no white noise button on the Kindle to mask her snoring, which she says she doesn't do.
I'm hoping that the next Paperwhite will also have a 'record' button so I can prove her wrong.
Barring these two advancements, I'm thinking of setting up a series of bright lamps in the bedroom that I can turn on by remote control when she is asleep, in addition to a multi-track professional reel-to-reel tape deck.