User blog comment:Arbington/The Next Cycle/@comment-5038903-20120805033001/@comment-5337704-20120805114317

Honestly, Bioware wanted to kill off Shepard, throwing in an ending out of 7, were he lives, was probably more fanbased than anything else.

Even the catalyst stated he would of died do to his implants, if he "destroyed" the machine. But as to the ending, it is left up to your imagination, I do not believe there will be any future canon story of Shepard, alive, dead, or part of the machines...