Are there any plans to impeach Obama over Libya?

In one week the US will have been involved in military action in Libya for 90 days. According to the War Powers Act after 60 days the president must have authorization from congress to remain, and he has 30 days after that to withdraw if he fails to get authorization. Obama has not received authorization, and I have not seen or heard of any plans to halt military actions. Even though some say that it's NATO, not the US, involved, we are still shouldering 75% of the costs. Even more importantly, treaties CANNOT supersede the Constitution. Which means that no matter how you spin it, in one week Obama will be in open defiance of US law. Have any congressmen made plans to impeach Obama when this happens? Or will one of the most important limitations on executive power die a quiet death?