There's an interesting post on Lost Remote (a site focusing on social TV) looking at what some local TV stations are "pinning" on their Pinterest sites. The post suggests that, for now, there are five basic approaches to content - Food and Recipes, Behind the Scenes promos, Pets/Animals, Weather, and News.
For now, stations seem to be experimenting with various foci, but do seem to increasingly see Pinterest as another social media system that can be used to build relationships with viewers. The Pinterest approach seems to offer some interesting opportunities for both promotion and disseminating news and information.
Sources - What local TV newsrooms are pinning on Pinterest, Lost Remote
Great Ideas from Newsrooms Using Pinterest, Kim Wilson social media strategy for the journalism business blog (List of stations using Pinterest)