Perhaps what they mean is more spells for Mages, more weapons choices for tanks, more for all party members involving gear and tactics. Perhaps, too, there will be more choices such as Clerics and Rangers.
Battles might be more strategic than they were and require a good strategy plan in order to win them, rather than just overwhelm the player with a multitude of Baddies to make them seem hard. Less hack'n'slash and more thinking through a battle plan instead. Perhaps a stealthed Rogue will be crucial in evaluating a battle plan, and not just place traps and open locks.
It's not all doom and gloom. Bioware are aware that they have a lot to live up to with DAO. Their reputation depends on having a good, solid sequel that lives up to, if not bypasses DAO, in both content and storyline. I think people are dissappointed because there's no more Alistair, Morrigan or Leliana, having become attached to them. I felt the same way about Imoen in BG and was pleased to see her make a comeback. As Morrigan herself said, "You'll never see me again". Bioware were telling you it's over and done with. The Blight is over. Perhaps this time warring nations in Ferelden will be at each others' throats in a bid for power and you are somehow connected with it. The Rogue could develop into a Cunning spy. I'm fairly certain DA2 won't be a dissappointment, but whether it will live up to the standards that DAO has set remains to be seen. I would imagine that having different voiceovers for all members of the party is expensive and would probably not include the voiced interactions that took place in DAO.