Credit Card Act for people under 21?

I(19y) unlike apparently most of the college students use my credit card wisely. I comprehend the new credit card bill that just passed will require people under 21 to either have a co-signer or establish they have income.
My question is how would the bill(when it actually goes into affect next year) affect people who are under 21 now and have credit cards? I have 2 credit cards and would I now have to establish I have an income when I get my 3rd card?