NEVER.
:)

Answer is never! The more consoles sold, the more difficult the wii's task becomes. The wii could only overtake the 360 + PS3 after 2011 but then, the wii 2 would already be knocking!

February 09

I doubt Kid Icarus would be able to do it, there hasn't been a kid icarus game in a looong time so hardly anybody in general would probably know who he is.  Pikmin, starfox, and animal crossing more than likely not.  A new Zelda game would probably be the only one, but there hasn't been a new Zelda announced any time soon.

July 09

January 2011.

Each percentage becomes harder and harder to gain, but Nintendo could climb to 50% in a few Holiday Seasons.

I came up with the same results the OP did. Put me down for July, 2009. (Something that may have an impact on PS3 sales this Christmas is it will be the first holiday season since the HD format war ended.)

I think never , once the 360 and PS3 get good price points in america the Wii may still outsell them but not their total userbases combined.

Edit : I hadn't realised how far ahead the Wii is , um put me up for Summer '09.

Um animal crossing ds sold 9 million. Pokemon sold 15 million on the ds alone. Zelda sells about 5-7 million. THen they have the wii series, and new ips. Nintendo has alot up their sleeves. Then nintendo has a whole bunch of smaller franchises that if more than one come out at a time could sell systems. Nintendo still has alot left.

June 2009, since the current gap is 5.02 million. It seems that the PS3 and 360 are playing a zero-sum game in terms of sales. PS3's gains are mostly at the expense of the 360's. The public perception of the HD consoles isn't helping their cause either, and that diminishes the effects of any price cuts that might appear.

As for deathgod33's argument about "when the PS3 and 360 drop to accessible prices", I'd like him to put himself into the shoes of the companies' CEO. Is it even economically viable to release a US$250 PS3? They were suffering losses even with a $599 launch price, so why go even lower? If something were to be priced at US$250, they are going to have to strip away many of the features in the hardware to make it cost effective, thus going against their marketing emphasis on BluRay and "next gen all round entertainment platform".

As for the 360, it's at the accessible price of £160 here in the UK, and that hardly helps it. So public perception affects sales in a larger way than just price alone.