Discussion Question: Going Concern--Now a Explanatory Paragraph; Should It Be a Qualification on an Audit Report?

A question came to mind while working on the accounting part of the Twelve Blogs of Christmas this week--at present, auditors may (and usually do) provide an unqualified opinion with additional explanatory paragraph to businesses with significant uncertainties as to whether they are a going concern. While auditors are allowed to disclaim an opinion on going-concern grounds, there is little evidence that this happens with any regularity.

Is this sufficient warning to financial statement users or should material likelihood of noncontinuation of the business be grounds for a minimum of qualifying the opinion on the financials? I'd like to hear your thoughts--and I'll try to come up with a comparable question for the tax readers of Tick Marks.