Who Wins in Credit Card Changes?

As Congress' credit card Bill of Rights works its way through the Capitol, it's hard to find the clear-cut winners and losers. Depending upon the final rules, I am betting that those most in need of credit are going to get hurt. Or perhaps it's just a measure to create additional clarity for consumers, but are there really any consumers out there who don't know that if they default, their rates can skyrocket? Or that a 0% teaser rate is only good for the stated amount of time?

Today's WSJ picks up another related matter. Retailers are pushing for the ability to give discounts to those who pay with cash, which practice today conflicts with many of the card company contracts. I'm in favor of this because I believe a store owner should be allowed to create any pricing structure he so desires - and if the card companies don't like it, they can choose not to accept that retailer as a client. Obviously this would help those who pay cash and hurt either those who pay with credit cards or the credit card companies or banks themselves.

Ultimately there are winners and losers to all of these changes, some of whom undoubtedly will not be what Congress expects (ie. those who need credit probably won't be able to get it). Why is it that Congress should be picking these winners and losers in the first place?