Not surprised at the lack of info until E3. Were in for a BIG one, though.
I doubt they would make a big deal about Smash Bros at E3 with it being the highlight of the whole show, then when the presentation starts shove Masahiro Sakurai onto the screen, have him say "Hey guys, Sakurai here. Just letting you know that Yoshi will infact be playable. That is all. Please stay tuned for a dedicated Smash presentation in September. Have a nice E3!" And then cut to Pokemon 8. They know theyve gotta rock the show floor with those 20-30 minutes of Smash Bros.
Speaking of which, E3 will be the first time in a long while weve seen Sakurai on video! Hopefuly he will continue his hamon anti aging process. Though, if the pictures have anything to say, he kinda let himself go...