UTJ is not part of the government today, but everyone seems to think that they will join eventually. In fact, today I heard the following theory (on Radio Kol Chai, a Charedi radio station) which makes a lot of sense. In many ways UTJ is happy about joining the government after it was already created. This gives them an alibi for their voters. When Olmert comes to do the disengagement and people ask UTJ how they can be in the government, or when the voters ask how come the child payments aren't restored, etc., they have an alibi, they didn't create the government, Shas did. They only joined to save what they could after the government existed. Olmert had a government without them anyway so they are not to blame.
Now, Meretz is providing them with another alibi. They will say they joined because it was either them or Meretz so they had no choice but to try to minimize the damage and save what they could.
In short, I would be very surprised if UTJ does not end up in the government.
One last point, there is no way that this government will last more then 2 years at best.