Speaking to IGN during GDC, Bioware's joint-CEOs Greg and Ray (saves typing) said that prior to battles, which will be proper real-time, players will be able to plan strategies to use, and then swap characters as the fights unfold too. Characters will fit into what sound like fairly standard archetypes - long/short range specialists, healers, etc. - but during the creation phase you'll be able to specify what you want, including the sorts of special attacks they have. The game will also use what's been pegged as Bioware's traditional weapon and armour progression trees.