Even local news channels are set up to handle just about anything. You can't go wrong with low-compression jpegs. Remember that HD has the same colorspace as sRGB, so sort of like on the web don't send them ARGB. Keep the post processing down and don't sharpen at all. Avoid large black areas, deep shadows, blown out white areas, or important textures above about the 190 level (for 8 bits). HD is 1920 x 1080 max, so 3K to 4K wide jpgs should more than handle it with some headroom to do kinestasis moves. In PS you can invoke Filters->Video->NTSC Colors to limit your gamut to whatever can actually be successfully broadcast, but that's really sRGB these days.
Try dropping a few images into whatever movie editor came with your PC or Mac and burn them to a DVD. I have found that even at NTSC quality still images usually manage to look really great on the TV screen.