The Drummond Group refused to certify our implementation because they do not certify components, but only "full products that are not programmable" (whatever that means).
I personally am not impressed at all with the Drummond Group. It appears what they are really after is protecting their testing "franchise" and the ability to charge exorbitant fees. At the same time, AS2 is so simple, there is really no need to go through interoperability testing with every product out there.
If the Drummond Group really cared about the industry, they would do testing against a reference implementation of the standard, instead of testing every product against every other product and exponentially increasing their work (and the fees they collect).
From the vantage point of a decade of experience with Internet Protocols, with almost every Fortune 500 using our IP components, I can tell you with assurance that the Internet relies on many protocol stacks vastly more complicated than AS2. Yet everything works and interoperates without any real need for an "overseer" like the Drummond Group.
If the "grocery industry" thinks otherwise, well, as long as they are willing to pay for it, that's really their problem. All I can tell you is that we have pilots (IP*Works! EDI is still Beta at this time) with a number of companies, and the Drummond certification issue has never come up.