NEW YORK ( TheStreet) -- Whether you watch a lot of TV or not, you are probably among the 78% of U.S. households that own a flat-panel TV. And you probably bought your first one last decade, when the TV world went digital and high-definition sets went mainstream. This decade, however, TV sales have slumped. Consumers said ho-hum to 3D TVs and Smart TVs. But business may be picking up as new technologies finally hit the market and prices continue to decline. If you're ready for an upgrade or just interested in what's next, here are the top five trends in TVs right now: Ultra-High Definition -- If you thought HDTV was an improvement over standard definition, ultra-high definition is astounding. The technology is also called 4k TVs, referring to its resolution, at 3840×2160. That is double the number of vertical and horizontal lines and four-times the pixels of current HDTVs, which are up to 1920x1080p. One of the first UHD sets showed up last year from LG ( LGEAF), which sold an 84-inch set for $22,000. The good news is that prices have come down and, for some, in size, as well. Sony's ( SNE) 55-inch XBR 4K Ultra HD TV is currently $3,999.99. The bad news: 4k video content is rare. No one is broadcasting it, although companies are working on it. Netflix ( NFLX) hopes to begin streaming 4k content within two years. Curved OLED -- Another flat-panel technology called OLED, short for organic light-emitting diode, promises better picture quality, lower energy use and a curved display to make viewing more immersive. The first sets showed up this year in the U.S. Samsung's ( SSNLF) 55-inch KN55S9C has just shipped to specialty retailers nationwide and will set you back $8,999.99. Two-in-one viewing -- Samsung calls it Multi-View. Sony calls it SimulView. The point of dual-screen viewing is that two or more people can stare at the same big-screen TV and watch different shows. (Samsung also offers a 75-inch set with the capacity for four people to watch four different shows simultaneously.) Of course, users must wear special glasses, which are also equipped with surround sound.