So, a week or two ago, I totally thought out that Adventure mode would be multi-player, and that the second player would have some kind of super-jump.
I was thinking back to our Kriby games, specifically the SNES two, and in both Super Star and Dream Land 3, there was a second player option that featured similar characteristics.
I actually expected either Gooey to return or that Sakurai would create a second player, though, and not have the second player be the back-up for the stage.
Now, I'm going to call it here, but I predict a mode where four players race through an adventure stage to collect power ups hinted at here, then duke it out at the end.
Also, I predict that since characters can gain strength in adventure mode, there will be downloadable new difficulty levels that basically give the computer players a handicap and add in tougher enemies. Also, Co-op will be available to play online, as well. That's my guesses.