I was never really fond of the Smash Ball item. I kind of wish you earned a Final Smash through good old fashioned pwning to fill a meter though the addition of a meter could complicate the game a bit.
Also, I know they already revealed how Zero Suit Samus would work last year, but I was hoping they would re-consider and make her a separate character. I was also hoping they'd make Samus more like she is in Metroid 3 and give her the stacked ice beam, a charged shot would temporarily freeze enemies. With a little tweaking, that could've added a lot to Samus' character in Smash.