I've used it in dishes in place of ground beef, but it definitely needs something to kick it up. Ground turkey is pretty bland. I've used it in sloppy joes, in spicy tacos, in chili with beans - all dishes which carry a lot of flavor on their own so that you can get away with using a less flavorful meat.
Yeah. My wife is not a fan of ground beef. She's not a vegetarian or anything, just not a big fan of red meat. So at our house, ground turkey is the go-to substitute for things like spaghetti with meat sauce, or enchiladas. Basically what fourputt says is on the money. It carries very little flavor itself, so you better stick it in something that has its own kick.