In regards to my previous post on what should be called Merrick Bank v Savvis, here is another blog post from Dave Navetta that goes into glorious detail about this case and why we should be watching it. An excellent article.
Please note that a potential analogue for security assessors are lawsuits by investors against accountants. Both engage in attestation services that are known to some degree to be relied upon by third parties. There are numerous cases going both ways (some finding liability/some not) with respect to accountant liability to investors who relied on inaccurate financial statements.