they should work a deal with Sony where they produce games exclusively on the playstation but Sony get a very tiny cut of the money.
Win - Win Nintendo has higher profit margin they no longer have to support a hardware system, Sony gets a small cuts and gains a younger fanbase from Nintendo they will be buy other games eventually.
End of 2009 Predictions (Set, January 1st 2009)
Wii- 72 million 3rd Year Peak, better slate of releases
360- 37 million Should trend down slightly after 3rd year peak
PS3- 29 million Sales should pick up next year, 3rd year peak and price cut