"What benefits have been modified, resulting in litigation? ... What is the central claim being raised in benefits litigation? ... What is the key consideration involving Contract Clause claims? ... How does the Contract Clause analysis in pension benefits litigation differ from COLA litigation? ... What benefit changes for current retirees have been upheld? ... Several benefit modifications involve changing future accrual of benefits for current employees. How have courts analyzed these changes? ... What future benefits litigation is on the horizon?"