Originally Posted by Redeemed Jedi
I say that he never did die, even though the novel says so, but that he severed his connection with the force; hence the force blast that occurred. By doing so his presence in the force would not be possible to detect (Yuuzhan Vong ring any bells) which is why the two dark lords thought he was dead.
YES! And then they could make it so you start the game very weak in the force again. Seriously, they probably did something like this for the storyline so you don't start out freakishly powerful.