It was pretty clear by the middle of last year it peaked about February 2008 - Feb 2009. That said, there is also no evidence of a rapid decline and Sony only sold 30m PS2s at more than $200, Nintendo sold 55m Wiis at $250.

In the USA, Wii has had one price drop in 40 months, while PS2 was nearing its third price cut...and Wii is still ahead by ~6m (a year at the rate PS2 was selling in the USA)

USA Pricing History Wii vs. PS2

Launch:  Wii - $249  / PS2 - $299

Cut 1:  Wii - $199 (Sept 2009 - Month 35)

            PS2 - $199 (May 2002 - Month 20)

Cut 2:  Wii - ?

            PS2 - $179 (May 2003 - Month 32)

Cut 3:  Wii - ?

            PS2 - $149 (May 2004 - Month 44)

Basically, because of how long Nintendo has managed to go without cutting price, the company can engage Sony / Microsoft in a nasty price war if necessary over the next year - two years. A 30 million base with every system sold at $200+ is historical for the USA market though, and it will happen in four to five months, tops.

it should end up somewhere along the lines of

2008 > 2010 > 2009 = 2011 > 2012 = 2007 > 2013 > 2014 > 2015 = 2006 > 2016 > 2017 = 0

but last year wii had 8 months of 150$ price advantage over the playstation (don't really know about xbox but i think this also applies to MS console too)... this year is going to be 12 months of only 100$ price advantage over the competition... my 17mil (might go up to 19mil with very good holyday season and zelda) prediction its for, no wii price cut in 2010... in therms of software, wii doesn't have system sellers like its competitors IMO this year (yes zelda might bring some light into wii sales but not sure that comes this year)...

like i said, i am no expert...

It's a good thing you are no expert, all the experts predicted that the end of gen sales of the Wii would be 18 million..

The Wii does not sell based on such things as "price advantage over the PS3" - the Wii sells on its own merits. 2010 will see the greatest game releases on the Wii of any year, beating even 2008

Still, the Wii is close to outselling both consoles this year. I think it is a gimmick console with only a few must-buy games, but a lot of people are buying it because of the motion-controls. 

2008 was the year with the biggest demand, but It is still selling 20 million every year.

Motion Contols do not sell games. Just look at the sales of third parties on the Wii. It's the good to great software that sales the system. For example, New Super Mario Bros. has lifted the sales of the Wii in every region thus far and helped the Wii break the single month sales record during the holidays that was held by the PS2.

I think it'll be pretty steady overall this year compared to last year. 2008 may have been a peak but I don't think sales will fall or rise significantly year over year overall wordwide.

yes wii has already peaked, but it will not fall fast, so don't worry, i predict crazy wii sales for at least another 2 years

Agreed.  They'll beat 2009 for sure imo (stronger core oriented lineup, stronger evergreens from last year, lower pricepoint) but I think 2008 is just too far a goal.  2010 will be the 2nd peak, then it'll start to decline YOY in 2011 and on.