For starters the 16 out of 486 titles are as far as I know derived from NPD sources so don't take into account sales in Europe, Australasia or Japan. There must be well over 50 titles that've sold over a million worldwide but it's difficult to tell thanks to Europe not having an NPD equivalent.
Secondly an executive from EA a while back stated that a PS3 title needs to sell over 500,000 to make a profit. Developing and publishing for the PS3 is much more expensive than developing and publishing for the Wii. Even if you ignore the media used dev kits for the PS3 will cost publishers and developers £18,000 each as opposed to dev kits for the Wii which will set back a publisher or developer £2000.
And I'm not too sure about the ownership of the Wii dev kits, but for any Sony dev kits once you've forked out your £18,000 you don't even own the bloody things - they're just leased! 
Development for the Wii is around 3-4 times cheaper than the other two current gen consoles...so I'd guesstimate that you'll only have to sell around 300,000 to make money on a game. And that's worldwide. 
And just in case you were wondering where I got the cost of dev kits from I was working in the industry for a few years. 