It's a vicious cycle, really - third parties don't put their mainline titles on Wii because they're afraid of them failing, so they put half-assed spin-offs instead, which end up failing, and then continue the same support because their previous endeavours failed.
However, MH3 did great on Wii, Guitar Hero does great, EA's sports games do great, RE4 did great, and so on. And both COD3 and 5, despite being "inferior ports," are both well beyond a million sales as well.
And next, we have Tales of Graces to look to, which will probably do well, as well as DQX whenever it comes out.







