Television providers have had a few years now to get used to online competition from over-the-top streaming services, though they should brace for more. As early as this year, they will be facing a new generation of online competition. Google Inc., Apple Inc., Sony Corp. and Intel Corp. are working on launching new over-the-top television services that may allow the viewer to flip through feeds from paid cable TV channels, including live programming. How long consumers have to wait for the tech giants to roll out their new TV products hangs on a multitude of factors—and their biggest...