Well at least until the most recent trailer for God Of War: Ghost Of Sparta, seen below. In the trailer they show how the game's story will be taking us all back, even further then the comics have, into Kratos' past. Showing a bit of Kratos' life before he became a general of the Spartan army and even a look at his home life. If you can call it that.
It also looks like they deviated a bit from the original brother story though. Originally they were split at around the age of seven and his brother was thrown from the cliffs only to be raised in Hades, by Hades, to be a warrior in his army. Doesn't look like Deimos, was really raised in the Underworld at all, but it does look like the grudge is still there.
Gods November 2nd is not coming fast enough for me!