The rejection of ComEd's grid plan by the Illinois Commerce Commission may lead to uncertainty regarding the company's future investments and earnings, potentially affecting Exelon's (EXC) stock in the short term. The requirement to file a revised plan indicates ongoing regulatory hurdles. ComEd's intention to seek a rehearing on key financial issues such as ROE and pension asset returns suggests potential financial impact. However, the exact financial implications are not clear at this stage, hence the confidence level is not at the maximum.