Looks like you can enjoy playing PlayStation 4 games while watching television after all. It's been known for a while that the Xbox One's HDMI In would support the plugging in of a PlayStation 4, and the setup is actually quite easy. Simply plug the HDMI cable from your PS4 into the HDMI In port located on the back of your Xbox One. Then plug your Xbox One into the TV.
Once the PS4 is turned on, select "Watch TV" on your Xbox One (or say "Xbox, Watch TV" to the Kinect). Your Xbox One will then display whatever is happening on the PlayStation 4. At this point, you are fully able to use the DualShock 4 to control your PS4 through the Xbox One.
By plugging the PS4 into the Xbox One, you are now able to use the Xbox One's snap feature alongside the PS4. Either the PS4 display can be snapped to the side by saying "Xbox, Snap TV," or you can keep the PS4 display enlarged while snapping other Xbox apps to the side.
You may notice some slight latency, depending on your actions, but the idea that you can play PS4 games while still making use of the Xbox One's Snap functionality is still pretty neat.
For those of you getting both system, do you plan on plugging your PS4 into the Xbox One?