Main difference between Wii and DS though, is DS is in a market with PSP where 3rd parties have been unable to make money off the platform considering so many piracy issues. DS however makes lots of money for them and with a 75 million userbase and lower costs to make, it's the ideal choice.
Wii on the other hand is in a market where while costs to make game on the Wii is cheaper and poses less risk, also has 360 and PS3 were making a game on both of them is of little risk considering software sells just as well on them 2 combined as it would Wii alone. Thus 3rd parties are allowed to stay in their comfortable zones which is why Wii may always be the platform used to pay for PS360 game productions. However Wii will still get all the mainstream games considering they sell beastly on the platform because its the mainstream console of choice. Which is weird why GTA hasn't been released on the platform.
