For the past few years, I've smoked a turkey crown without brining, having asked the same question here in 2010.
The first year I cut the skin back, and covered the breast in bacon. Subsequent years, I have simply put butter under the skin. Both methods gave excellent results.
I'm actually with friends for Christmas and Boxing Day this year, but I still like a bit of turkey. I'm planning to leave it until after Christmas, and see if I can get a bargain.