From the PlanetPlaystation.com feature preview:
"Now, while we await the next chapter of Super Smash Bros. for 3DS and Wii U, we have a new competitor entering the battlefield – and it’s Sony! The company announced its long-rumored PlayStation All Stars Battle Royale last week at an event in California, confirming what’s been rumored and leaked for months, and later confirmed with registered domain names. Sony recently invited us down to give the game a look, and to kind of confirm that it’s not a direct port of Nintendo’s Smash Bros. series."