Only drawing with intent to shoot...
... ignores the statistic that in over 90% of cases when a gun is drawn for self-defense, the attack stops without shots fired.
So, the odds are good that drawing the weapon will be a strong deterrent.
One can't count on the draw alone doing the job, and one should be prepared to actually shoot, but one should not discount the extremely strong possibility that the draw itself will deter the BG.
Some folks seem to argue that they worry about a brandishing charge in such instances.
My counter to that is simple: In order to avoid a "brandishing" charge, you are willing to let the situation develop to where you may have to face a "homicide", "manslaughter", or "aggravated assault with battery while using a firearm" charge; how does this make sense?
To the poster who said he wouldn't draw until he saw a weapon: better hope you're a faster draw than the BG if he really has one; also, who says he'll draw from his pocket? I wouldn't need to, with my 442.... A BG who actually has gun in pocket could just shoot without drawing.