Why would they show these games? First of all they won't be finished this year anyway plus it would probably trigger more "well, just another f-zero, and all they can roughly say is 2008". The chances that F-Zero will be on the Wii are nearly 100%, so why bother. Of course it's nice to have confirmation but there's always next year's E3 or even this year's Games Convention in Germany and I'd rather wait one year to actually see something of the game rather than the name only.
I also think that Nintendo need a bit more time to test online, after all F-Zero Wii would be a letdown if it did not feature 30 player multiplayer online races.
As per usual, well said.
It would be ridiculous if Nintendo had showed every single one of their IPs at E3, and even if they did, people would still complain. We all know that F-Zero, Pilotwings, Animal Crossing, etc are on the way, so just be patient (a quality not possessed by many gamers).