That change may happen, but I think Kolb will have to blow up at least one more time. Bobby Cox is fiercely loyal and probably isn't going to make any pitching decisions based on anything that happens at Coors Field.
This isn't a problem just limited to the Braves though. Teams are blowing saves and getting their closers hurt all over MLB. I can't ever remember a year when more teams had trouble closing out games. Makes you realize just how good John Smoltz was.