Dalek_Kolt
Smash Master
It's probably ludicrous to find a trend at this point, seeing as there's only been 3 games so far...Now I know it's been said over and over that because x character isn't in the game doesn't mean people won't buy the game anyway, but that's still ultimately incorrect. There are going to be those that aren't going to be interested because most of what they'll see are random characters like Miis and Wii Fit Trainer. Isn't it a game developer's goal to sell as many copies as possible? And look how Sakurai can accomplish that. By adding popular and well known characters. Sure there are already numerous icons in the roster, but the public is always looking for the new stuff. While Mega Man and Little Mac are a nice start, it'd be foolish to rely on them solely.
In short, the idea that Sakurai isn't going to add any more fan favorites is nonsensical, especially from a business standpoint.
But on average, there's typically been at least 10 newcomers per game. What are we at now, 6? and not all of the veterans have been announced yet?