The biggest mortgage securitization trustees are Bank of New York, Deutsche Bank, Wells Fargo, and US Bank.
The interesting thing about the American Banker article is that the trustees appear to be in a great deal of denial as to how much hot water they are in. No where does the story mention their biggest exposure: that they gave multiple certifications to the investors in the mortgage securtizations that they did indeed have the trust assets. If, as it now appears to be the case, that many mortgage loans were not properly conveyed to the trust (as in endorsed by the originator and all the intermediary parties specified in the contract governing the deal, the pooling and servicing agreement, and finally over to the trust), then all those certifications were patently untrue. Since investors relied upon these certifications (no one in their right mind would have ponied up for these deals if they had had any doubt that the trust owned the mortgage loans) and the failure to convey the notes is a big cause of problems with foreclosures, it would seem that the trustees are very logical targets for investor litigation.