Whilst Cersei Lannister is not as powerful as she was in 1.0, she is still a formidable card. The ability to discard two cards from the opponent’s hand should not be taken lightly. It is generally the case that card advantage leads to victory; as such, removing extra cards should help bring about defeat and ruin!
Cersei Lannister combines nicely with The Queen’s Assassin who can kill a character provided he is ambushed in on an opponent who has less cards in hand. Also with Tyrion Lannister, who gleans 2 gold from her intrigue challenges. Likewise, with Casterly Rock, Lannisport, Tears of Lys and most cards that center around the intrigue challenge type. As a result, she will likely find a home in most if not all House Lannister decks.