Today's Super Smash Bros. Direct revealed that Super Smash Bros. for Wii U will allow up to eight players to smash together—twice our usual volume of Nintendo-themed violence. Only some stages will be available in five or more player smash, as most of the normal ones are a bit small for so many people. Hyrule Temple, Windy Hill Zone, Palutena's Temple, Galaxy, and Big Battlefield are among these. Unfortunately, Eight-Player Smash will not be available online, so have lots of friends.
Source: Smash Bros. Direct