How much of a side project? Well, if the rumor is to be believed, it will be released in May, a bit before the Summer Olympics in London, where Samsung is one of the major sponsors, and has an abundance of projects around it, including ones related to mobile payments.
Now we learn that the Samsung M is supposed to be brimful of sensors for the sporty type in you, eventually all the way up to heart rate monitoring and other biometrics. The handset is allegedly also going to feature eye-tracking tech that keeps the screen fired up when it recognizes you are looking at it, and the accelerometer will be able to recognize when you are lying down, so the auto-rotation keeps the screen leveled with your sight.
Other environment-aware features are in store, too, like the phone's proximity sensor recognizing you want to call the person that just sent you a text message, and dialing their number automatically when you immediately press the phone to your ear.
Also, when you take a photo, the Samsung M is said to tag the people in it, and offer you to email it to them on the spot. Sounds pretty neat, even if half of this turns out true.