Indeed...unfortunately, I think that over time you're going to find that this isn't just an issue of sub prime lenders running into trouble. Mortgages are bought, sold, and transferred in ways that are unimaginable to the average person who pays a monthly mortgage payment.
I used to sell mortgage-backed securities through Wall Street firms. They were sold and gone, as far as my company was concerned. Then on the other side, I would sell the servicing to mortgage servicing ("lockbox") companies who collected payments and sent the proceeds (minus the servicing fee) along to the bond-holders. The people originating the loans are entirely fee-oriented and couldn't care less what happens to the loans after they are closed.