Apple announced its new MacBook during their Spring Forward event. This 12-inch model includes some new features that include a pressure-sensitive trackpad that can be clicked anywhere on the surface and detects how much pressure you are applying. Apple may include that same technology in their next iPhone, according to WSJ.
According to The Wall Street Journal the iPhone 6S and 6S Plus will include the force-sensitive touchscreen and will also be available in a fourth color: pink.
This is just a rumor for now, but highly plausible.