:I initially had a brief vacancy down there also, but during the match Cole stated that Punk was still the champion.  Kane then became interim champion, and Jericho was revealed to be replacing Punk at the 15min mark.  I've never seen a title made vacant -during- a match being held for that very title, but the way I see it, by the time we found out that Punk was not in the match, Kane was the man to beat and the title never really became vacant.  As you said, "in every similar situation in wrestling history" it goes vacant but, this situation is unique and sets a new precident.  The title really was never made vacant, which admittedly sounds weird, though I -can- see an arguement for stating it was for exactly five minutes: between Jericho's introduction and the end of the match.  I see it though as the match started with Punk as champ, and really can't be made vacant during said match.  If no one had become temporary champ by the time Jericho replaced Punk, then there would be no real reigning champion, and THEN it could be vacant, but otherwise, Punk just wasn't part of the match that was for his own title.