#4 A title can change hands on a disqualification
It's written in the rule books that a Championship can not change hands on a disqualification or a countout. The match has to end via pin or submission in order for the title to change hands.
Of course, in the past, there have been a number of matches that have seen something like this happen when the feud has become so intense that there have been added stipulations.
A disqualification finish definitely helps Dolph Ziggler because he knows how to get under Drew McIntyre's skin. He could bait him into attacking him with weapons or even make him so angry that he can't stop assaulting him and then he gets disqualified.
This would definitely get Ziggler the heel heat that he requires throughout this match and it would force McIntyre to be the underdog and have to prove that he has what it takes to be the Champion and come back from behind.
Ziggler has been around the wrestling business for a long time and he's a tactical genius, so whatever stipulation he chooses at Extreme Rules, you have to believe it's going to give him the edge.