If dark pit plays like falco vs. fox in Melee, I'm very excited about his inclusion. The characters did such wonderfully different things. Same with Dr. Mario. Dude's air punch is the hypest thing to land this side of a falcon knee.
And I like the F-Zero and Magicant stages so much that they're almost like new characters to me (even though they, too, were in the leak) :-D
Super-stoked about Bowser Jr. and the Koopalings -- definitely one of my favorite newcomers. Duck Hunt also looks great with all of the references to Hogan's Alley and Wild Gunman. Dr. Mario is very worthwhile with the pills, Tornado, new intro and Final Smash. Dark Pit has grown on me -- conceptually identical, but I like the flashy new effects on the arrows and Side Special.
Dream combo: Bowser Jr. vs. Greninja vs. Palutena vs. Shulk on the SNES F-Zero stage