The challenge for banks in the slower revenue growth environment is to become more efficient to drive down operating expenses. With the spread between the long end and short end being narrow, it's tougher for banks to make money.
Buyers are also more eager to do deals, because earnings growth is likely to slow. You can do a 'smokescreen' deal by buying an asset manager, commercial lender or processor, making it tougher to determine a company's true organic growth.