Nintendo actually did add the Wi-fi online play. I had my doubts when the announced the adventure mode because I thought that was to pacify us for not adding online play but they actually added it. All I can say is WOW this is the best Super Smash Bros Brawl update ever. The online play supports up to 4 players at once.

According to the Smash Bros site you can play via two modes “With Friends” and “With Anyone.” The “With Friends” mode shows players from your Friend list that are online at the moment and of course with anyone pulls random people online just like in Mario Kart DS and Mario Strikers charged online play. In “Friend Mode” you can also send short pre set messages. There are four messages for the four directions on the + Control Pad: Up, down, left and right.

The “With Anyone” mode will pit you against random players and the site stresses that you will not know each other’s names and the site claims that on anyone mode no win/loss records will be kept and no in game messages can be displayed.

More here.