Well this disscusion is going no where.
Adding a little more depth to a game isn't bad, but changing the overall core gameplay is bad. I think we can all agree on that.
Ex. MM series. Each game had slight differences that made each entry different from the last:
MM2: 2 diffculties, E-Tanks
MM3: The lenght of the game and returning RMs, Rush the Dog,
MM4: The Mega Buster, and hidden items
MM5: 9 RMs, an improved Mega Buster, Beat the Bird,
MMIV: Shoping for items
MMV: Mega Arm, Stardroids, Tango the Cat,
MM6: Rush Adaptors
ect
And keep in mind these games were all released within less than 10 years.
Each entry was different from the last, so as Shortie said, SSB4 will be different from the rest but the core gameplay will not change.
Anyway I'm off to lunch. Later.