The All Blacks have been pretty successful in 2012 and 2013 and for that reason, it would be hard for the New Zealand Rugby Union to make any changes to the coaching team. It just doesn't happen in rugby - a team going well, deciding to cut coaches.
South Africa did it after the World Cup: Jake White was successful and yet they got rid of him. That was rare indeed and probably driven by political agendas rather than rugby agendas.
I can't imagine the NZRU will do anything like that with the current set-up. How would they justify it?
I suppose, Ian Foster and Aussie McLean would be the two you would look at the hardest primarily because they are most directly involved in the way the team actually plays. Mick Byrne is a skills coach and Mike Cron still does most of his work around the scrum.
Foster has surprised m ea wee bit. He took the role after his time with the Chiefs where he wasn't particularly successful. But it's hard to argue with the results since he came on board with the All Blacks.