This CNNMoney.com article
has an interview with TCF Financial's CEO. Here's one interesting excerpt:
"This affects about 90 banks. But some of the bigger banks are virtually 50 to 100 times bigger than TCF," he said. "When you talk about little vs. big, Durbin may have taken out a gun, aimed at the big banks, missed them and shot me."
There's a bar graph at the top of the article with the title "There's Big Banks. And Then There's Big Banks." where you can see how much bigger the megabanks are as compared to banks like TCF.