Shovel Knight would be a great character to stick in to the series.
I don't think Goku, or any character from a TV show, would really fit into the Smash Universe. It's the same reason why it would be a turnoff to add in characters from Street Fighter or Tekken - these characters are already billed as fighters with their own references, so it just seems broken to have Goku pummeling Kirby or Pacman.
Sex does indeed sell - just usually not quite as overtly as these ads.
Totally agree - and the bundle for $11 for all three games? Awesome.
I think Nintendo would be wise to simply look at the top-selling games for the console and release those in batches of 3 to 4 at a time. Obviously the Rare classics as well as the quality Mario titles are at the top of my own list, but games like Turok and the WCW games are nice as well.