Nassau County Executive Edward Mangano will deliver his fourth State of the County speech Wednesday at 7 p.m., and it should be one to watch. The county faces extraordinary financial challenges. Nassau is running an operating deficit every year and has failed to pay off at least $300 million in property tax refunds. One big tool for addressing the finances, a tricky $750-million lease of the sewer system, appears dead for now in the Sandy-spewed water that damaged the plants. And the other two remedies -- a wage freeze imposed by the state control board overseeing county finances, and the move to no longer pick up the cost of tax refunds for money kept by the school districts and municipalities -- are imperiled by court decisions. The state of the county is not strong, and Mangano must address this, either with new ideas or better ways to implement the old ones.