They will keep rising as long as nintendo exceeds their forcast. They will remain steady if nintendo meets expectations. And obiously will fall if they do not.
There is alot more to it, You have to remember that the Market is driven by 2 things... fear and greed
Right now fear is what is controlling the market... It has nothing to do with Nintendo with their stock falling... Buy now, they will recover that 10% in no time... and then you make a quick 10% profit : )
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