Yep, it has been discussed.
Sure it is an option! If your company is not required by a customer, owner, etc. to have a registrar's cert. and you have the discipline to implement and follow the standard without an outside party looking over your shoulder, then by all means self-declare. You save money, save hassle, save having to do things just because an auditor says so, etc. There is nothing in the standard that says it is only useful if a cert is issued, in fact many people feel otherwise, including, I believe, an ISO advisory group.