Prime Minister Benjamin Netanyahu has offered Tzippi Livni, the head of the opposition and chairwoman of the Kadima Party, to join his government. She hasn't ruled it out. I think it is very important that Kadima stays in the opposition. Hopefully, the threat of many Kadima MKs to change parties and Shaul Mofaz's demand for new elections for the chairmanship of Kadima won't lead Livni to the wrong decision.
Netanyahu is one of the worst prime ministers Israel has ever had. Despite this, there is no real opposition against him other than radical settlers. The parties in the parliamentary opposition are too diverse to form a cohesive counterbalance to the government, and even Kadima is oddly silent on its failings. What needs to be done is for Kadima to be united somehow and for more criticism to be lodged against the government, not to join it.