This excerpt taken from the PNC 8-K filed Dec 2, 2008.
Note 4 Estimated Annual Cost Savings:
PNC expects to realize approximately $1.2 billion in pretax cost savings following the merger, which PNC expects to be phased in over a 26-month period. These cost savings are not reflected in the pro forma financial information. Although management anticipates such synergies and cost savings to occur, there can be no assurance these synergies and cost savings will be achieved.