WiiWare developers do not get paid by Nintendo unless their games sell over a specific number according to reports. WiiWare developers do not get paid by Nintendo unless their games sell over a specific number according to Gamasutra publisher and Inde...
He believed the threshold was in place to ensure developers only submitted quality games which had a good chance of meeting the required number of downloads (ie no shovelware). Carless also believes Nintendo may be changing the minimum threshold policy in the future.
Source: IGN
Hands on events coming before launch.
Mario Kart 9, 10? We don't know.