Congress approved stricter regulation of the way credit card companies operate last week. Some argue that banks will suffer and take away perks from some of their best customers by raising rates, lending less, and increasing fees for everybody.
A recent MarketWatch.com article suggests that credit unions might benefit from the new laws since they'll be impacted less. Presumably your bank will make unpleasant changes and drive you to do business at the credit union. I'm not sure if this is true, although credit unions might have been more attractive to you in recent years - before the new regulations.
Credit unions are nonprofit organizations "owned" by customers. The idea is that this gives them different incentives than a business owned by profit-seeking shareholders. In addition, credit unions have the advantage of avoiding taxation since they're nonprofits.
The ownership structure and tax advantage often work out in customers' favor - in the form of better rates and kinder treatment. However, some credit unions just act like banks with a tax advantage, and they don't treat members any better.
Further reading: