The shape of TVs to come might be even wider than wide-screen. Today's high-definition sets evolved to a rectangular 16-by-9 shape from the more square analog TVs. But a wider 21-by-9 display standard is in the works at the Consumer Electronics Association.

Vizio's 58-inch 3-D LED CinemaWide is expected to be the first 21-by-9-inch to market. It's due in stores in March in time for the NCAA men's and women's March Madness basketball tournaments and will be $3,499.99, including four pairs of 3-D glasses.

plans 50-inch and 71-inch CinemaWide models in the second half of this year.

On CinemaWide sets, Hollywood films shot in aspect ratios wider than 16-by-9 will automatically fill the 21-by-9 display without black bars on the top and bottom. Other 16-by-9 content can be scaled up to fill the screen, too.

Viewers can also use Facebook, , Twitter, Yahoo TV and other applications on the left side of the screen, while the full 16-by-9 video fills the remainder of the display.

"We wanted to give consumers a good choice to watch movies and ... standard TV while you use the Internet," said John Schindler, vice president for product management at Vizio. And for prospective TV buyers looking for something more modern in their homes, "this offers a new look and feel."

The CEA is in the process of developing a standard that would allow 21-by-9 content to be carried over current HDMI (High-Definition Multimedia Interface) video cables.

Vizio TVs have built-in technology that will allow them to work without the CEA's updating of the HDMI standard.

"We really wanted to lead that change," Schindler said.

Ultra-wide video "is closer to a ," said Brian Markwalter, vice president of technology and standards at the industry trade group.

"That is the aesthetic to it - to get the more sweeping panorama," Markwalter said.

Faced with expected slowing sales, TV makers are adding various features to sets, including 3-D and smart technology, to spur sales.

"The manufacturers are trying to differentiate and guess ahead of whatever news is coming from Apple," said industry analyst P.J. McNealy at Digital World Research.

Apple is expected to roll out its own Apple-branded TV this year.

Vizio's CinemaWide models display 3-D content and incorporate more than 180 Vizio Internet apps. "When you have a CinemaWide display in 3-D in your living room and you are watching a 21-by-9 movie, that can be as good or better than some theater experiences," Schindler said.

For multitasking, the sets have built-in Wi-Fi and come with a Bluetooth keypad for perusing apps. "Consumers want to do more on their display," Schindler said. "But in the living room, people want a simplified experience" that uses one device for Internet and standard TV.