Synopsis As Introduced Amends the Electric Service Customer Choice and Rate Relief Law of 1997 in the Public Utilities Act. Changes the definition of "mandatory transition period" to include the period from the effective date through the date on which the Illinois Commerce Commission has approved declarations of competitive service for all classes of service offered in the service areas of all electric utilities that, on December 31, 2005, served at least 100,000 customers in Illinois. Requires the Commission to order certain utilities to file and implement tariffs to reinstate all rates charged to the electric utilities' customers on December 31, 2006, within 10 days after the effective date. Requires the Commission to order the electric utilities to refund to the utilities' residential customers any amounts charged to such residential customers, from January 1, 2007 until 10 days after the effective date that exceed the rates charged to the electric utilities' residential customers on December 31, 2006. Provides that the refund must be issued within 30 days after the effective date and shall include interest on the full amount of the refund, at the same interest rate the Commission requires utilities to pay on customer deposits. Prohibits the Commission from taking certain actions prior to 2010 with respect to (i) initiating, authorizing, or ordering any change by way of increase or (ii) in approving an application for a merger, imposing a condition requiring any filing for an increase, decrease, or change in or other review of a utility's rates or enforcing such a condition. Makes other changes. Effective immediately.