"I'm just hoping that the World Cup is the catalyst that really galvanises them and I think it will be and they will go again. I don't think they've had the same buildup as they've had for 2015.
"And maybe when Richie McCaw and Daniel Carter and Conrad Smith and Ma'a Nonu and Keven Mealamu all move out together there's probably going to be a little bit of a drop. So that may be the case.
"They've got a great side and I think if they can galvanise on the World Cup and it pulls them together, they will be very difficult to beat."
Despite his slight doubts and acknowledgement of the rising challenge from the Northern hemisphere, the 72-year-old still has faith in his former protégé Steve Hansen's side – saying his gut tells him the All Blacks will make it a three-peat.
"You need challenges don't you and no doubt the Northern hemisphere is getting better. Wales have been impressive. I think they're real contenders … Ireland have given the All Blacks a couple beatings in the last three years and they have never done particularly well at Rugby World Cups.
"And England always should be good, they've got the biggest resource in the world. They should be the best in the world and they're not. But they've certainly got a lot of potential and a lot of experience.
"I think it's going to be a really interesting Rugby World Cup. I think if the All Blacks play to the peak of their powers they will do the business but that's the question: Can they get up there again and do the job? My gut tells me yes but I think it's going to be more competitive than last time."