This is impossible to predict -- the trend right now is that it will continue forever.  The biggest issue I can see going forth is that there aren't any good PS3 releases in the immediate future, Lair fell flat on its face and Heavenly Sword looks to be repetitive.  A couple of good PS3 releases could reverse the PS3's fortunes temporarily.

Of course, the Wii is still selling out everywhere and there are a lot of huge releases coming up.  I know there is Mario Galaxy just around the corner, which is likely to sell > 10 million by the end of 2008,  but the big possibility is Wii Fit, which could really break open gaming and bring it to markets that have never considered it before.

Wii Fit will surprise a lot of people in terms of sales.  I believe it has the potential to be huge -- not with initial sales, but with very, very long legs and it may sell the system to places where games would have otherwise never gone.

According to the site Wii US is again larger than PS3 WW.

wow you're right, I didn't think it was gonna happen.

Everyone is a mature 16 year old one time in their life.

MP3 gave the Wii the boost it needed in the Americas to get it more than just a couple thousand ahead of the PS3 WW. In fact, evidently it's about 80,000 ahead. US sales alone aren't reported on this site, but you knew that

Wii America has really shot well ahead of the WW PS3...

One other point of interest, the Wii America is tracking higher then PS3 and Xbox 360 World wide over the same time frame.

Quite a huge step up i'd have to say.