Easy Studios - the other guys that make Battlefield games - have introduced the classic Battlefield game mode Rush in Battlefield Play4Free. The game mode is live as of this morning, ready to play right now.
Rush Mode, if you're not familiar with it, is an objective-based game mode in which players take turns defending and attacking points on the map. The defending team begins with 2 M-COM stations that need to be defended, while the attacking team is bent on destroying them. Attackers can either successfully plant charges on the M-COM stations or inflict enough heavy damage to put them out of commision.