As a Nintendo fan, this literally makes me sick. SSB is a staple of Nintendo, and it's not right for another company to basically copy and paste the game and call it their own. Hopefully Nintendo will sue or something, because this is so wrong.
What a silly outlook. I prefer to see it this way:
Smash has never had serious competition. Therefore, they've set ALL the rules about how it's "genre" of Arena, Multi-player fighting should play out. This is... kinda boring.
Some of the best changes to fighitng games came from SNK and Capcom's rivalry. (And the little guys who pecked at their heels, too!) They each went in their own directions, and brought new things the other would not have thought of.
For us, as consumers, this rocks! For them, as competitors, this also rocks, as "creativity" isn't restrained to simply resting on their own shoulders.
So let the ripoffs commence! Let Sony "prototype" ideas for the next Smash, and put a product into the wild, so Nintendo can take notes, and put their spin on them in Smash! Lets hope Sony continues their series, and does thie same. It's a good thing for everyone involved!