An opinion by a panel of the Federal Circuit recently held that the enforceability of a patent is determined by the "would the information have been important to a reasonable examiner" standard, and not the (arguably) narrower standard established in 1992 in 37 CFR 1.56. For reasons I wrote about long ago, I think that's the right result.
It's also an important rule of law that may create some problems for patent lawyers. Rule 1.56 defined information that had to be disclosed to the Patnet Office as being either (1) information that, by itself or in combination with other information, would establish the invalidity of a claim or (2) information that contradicted a position on patentability the applicant was making before the Office. The "statutory" standard was no so limited. Suppose (and through conversations I've had, I believe this has happened) last year a lawyer decided not to submit information because, though a reasonable examiner might have found it important, it was not within Rule 1.56. Suppose today a lawyer is using a form that explains the duty of disclosure to applicants by parroting the language in 1.56.
If either resulting patent is issued, unenforceability could result. In the former case, the lawyer will may only have his lack of intent to protect him. In the latter situation, if the client's failure to disclose information is held to be inequitable conduct, the client may sue the lawyer for (allegedly negligently) failing to advise the client that it was not enough to comply with 1.56.
This is more a heads up for those of you out there. I've had several conversations with lawyers who didn't know of this opinion, or were not aware of the possibility that 1.56 would be irrelevant to enforceability. All compliance with 1.56 means is that the OED can't take your license away.