They aren't the normal, but a sign of the normal. Games like Chocobo's Dungeon and Crystal Chronicles King popped up on the PS1 and PS2. They were largely in Japan, but they were signs of S-E's (and their former selves) large fanbases, that they were willing to add niche games to expand.
If you want an example why this won't hurt the Wii, look at the DS. It has a Slime spinoff game or two, a Chocobo spinoff game (which sold as well as Dungeon on the Wii), and even a Kingdom Hearts spinoff.
By what you are saying, this would be a sign S-E has no faith in the DS. Yet then why is DQ IX on the DS? Because the system is selling well enough they know their fans will follow. Fans followed Final Fantasy to the Playstation, and that was just the existing ones.
So with the Wii's high sales, it's safe to say S-E assumes fans would follow their major franchises to the Wii, even Kingdom Hearts. So Kingdom Hearts would not make the Wii fail in S-E's eyes.
A flashy-first game is awesome when it comes out. A great-first game is awesome forever.
Plus, just for the hell of it: Kelly Brook at the 2008 BAFTAs
