No morph balls in '01 prime 1 demo either, but lots of action.
Oh I remember how the atmosphere seemed so cool with this preview. The final game was completely different though, much more "shiny" and less organic. Not that I'm saying Prime was bad because it wasn't, but this felt more like super metroid.
Oh and they did show some morph ball in the art there, the samus studies were all to see how to fit a human in the varia suit, including samus all curled up, I'm pretty sure that was for the morphball.
I've always dreamed that someone would make a whole transformers-like transition from suit to morphball, although it seems imposible to actually come up with something like that that works realistically, but some designer should be up to the challenge! the little blocks coming around making the suit in the trailer seemed kind of lazy in my eyes.