I agree with this much.  The game most likely wouldn't have sold much more on Gamecube if anymore.   It was just released at the end of the PS2s life when nothing but well-advertised games really had a chance to sell.  Gamecube games were selling poorly at the end of 06 too.  Either way, it should sell much better on Wii.  Hopefully it will be a million seller on Wii or at least between both platforms.

According to Vgchartz, Okami has sold 150k in Japan.  So let's add that:

Japan: 150k

And according to this source, Okami sold 270k by March 07, so with legs it might have sold 300k in America

America: 300k

And while the game was completely ignored in Europe, a large userbase must have gave it some sales. Let's go low and say 50k.

So, what we end up with is...

Japan: 150k

America: 300k

Europe: 50k

Total: 500k 

@Montana: If the Wii version sells more then 270k copies then you have your proof that if the game came out on the Cube it would have sold better (that is if you believe most Wii owners were also Cube owners or PS2 owners)

Maybe I'm reading this wrong, or interpreting it incorrectly but your source states this:

"In fact, since its release in September of 2006, the game has amassed about 270,000 in sales..."

To me that means in total sales, till March 20th, 2008 it has sold in total, 270k. Did I miss where it stated that this number was only for the US?

300k WW seems good to me considering how much Capcom is asking for the game and the very minimal improvements.

@MontanaHatchet thanks for the info

500,000 +
easier said than done

1.2m

I'm buying this to support my favorite developer. Maybe I'll buy 3-4 copies.

This game should have been for the PS3.

Uh, only hours ago you lectured people for saying RE5 should have been on Wii... please don't be a hypocrit.  Games are what games are.  Play them and enjoy them.  Stop showing console bias.

I can show all the console bias I want. You can't get mad because I have a favorite console, lol. 

And unlike RE5 people, I will buy and enjoy the games I want no matter what console they're on. I will be buying Okami for Wii. If were for the 360 or PS3 as well, I would buy it fro those consoles, too.