I think the Challenge Cup should come back because it could improve relations between the AFC and OFC.
Here is a list of unoffical matches
FIFA World Cup
12 June 2006 Japan 1 - 3 Australia
FIFA Confederations Cup
16 December 1997 Saudi Arabia 1 - 0 Australia
7 June 2001 Japan 1 - 0 Australia
18 June 2003 New Zealand 0 - 3 Japan
20 June 2009 Iraq 0 - 0 New Zealand
International Matches
12 August 1973 New Zealand 0 - 0 Iran
17 October 1982 Australia 3 - 2 South Korea *
21 June 1987 South Korea (5) 0 - 0 (4) Australia *
9 July 1988 Australia 3 - 0 Saudi Arabia
6 September 1990 South Korea 1 - 0 Australia *
9 September 1990 South Korea 1 - 0 Australia *
22 May 1994 Japan 1 - 1 Australia
29 September 1994 Japan 0 - 0 Australia
15 February 1995 Australia 2 - 1 Japan
10 February 1996 Australia 1 - 4 Japan
14 February 1996 Australia 3 - 0 Japan
*Asian Games winners
That is what I think.