A few thoughts after watching some vids:
1. I like how the Smash Ball floats around.
2. The character portraits by the damage percentage are pretty unnecessary though I like how they become transparent so as not to block the action. Such a simple idea took some 8 years to implement...
3. Was the beam sword blue? It sure looked like it. "George Lucas is gonna sue somebody..."
4. Still haven't been able to confirm if swimming has made it in the game, but I'm assuming it hasn't. If all you could do was swim and jump, that would open up gameplay possibilities. For example, you see an item floating there in the water and you want it but you'll be a sitting duck, open to projectile attacks and opponents jumping after you to hit you right before you get the item.
5. Color palettes are back... though I'm still holding out for alternate costumes.
6. The Metroid stage has basically been exactly the same through all 3 games with lava/acid (or is that Fuel Gel?) rising/falling. You'd think they'd try something different. Lava seems to come from the sides too... but it's still all too familiar. And I know I'm nitpicking, but shouldn't everyone except Samus lose health in Norfair due to the extreme heat and lack of the Varia Suit.