Reheat a turkey without drying it out?
You want to use a gentle heating method. For this sort of thing, I prefer steaming. It will gently bring up the heat of your food without wringing the moisture out of it. This is especially helpful if it's already cut into relatively small portions, such as slices of breast meat. Spread everything out on a single layer on the steamer basket before hand.

Warming drawer would be my second choice. Slice, add a few teaspoons of water, and cover and add to your warming drawer, set to your target temperature.