First of all, Wii Sports is the first groundbreaking title of the generation. Second, if Nintendo OWNS a studio, that makes them FIRST PARTY. Strictly speaking, there is no such thing as a "second party developer." Either a console-maker owns 51% of a company, or they don't. A "second party game" is a game made by a third party developer, but published by the first party, like Donkey Kong Country or Gears of War. And lastly... There are a handful of "epic" games on the Wii, but this is a thread in the SALES DISCUSSION board. Who cares if there aren't "epic" games, if all those third party developers are working on the next Nintendogs? (Well... They aren't... But non-epic games from at least a dozen different publishers have good sales potential on Wii.)
"[Our former customers] are unable to find software which they WANT to play."
"The way to solve this problem lies in how to communicate what kind of games [they CAN play]."
Satoru Iwata, Nintendo President. Only slightly paraphrased.