Page 24 of the Securitization Prospectus lists all the sellers in the latest securitization that account for more than 10% of the total securitization. Here is the list
JPM, with 29.2%
Charter One Bank, with 37.2%
GMAC Bank, with 11.5%
Others, with 22.1%
Charter One Bank is the number one in this list, and BAC is not in the list at all, so I would say that diversification is in progress.