My understanding is that it is in continuity. Kinda like Byrne's Man of Steel. But not totally starting everything over, just tweaking Superman's origin up some.
Oh and by the way. I got it and suprisingly really liked it. I'm one of those people that love Superman, try out his books every so often, but for the life of me just can't get into them. I'm kinda hoping Birthright may be the beginning of something new for Superman that I may be able to get more into this time around.
