I've run into problems with some of my museums hiring hacks to build their website then calling me to fix things when it inevitably goes bad, so I'd love to see a certification program happen. It sounds like something suited more for WordPress Foundation to oversee than Automattic. There could be two or more different levels of certification: an entry-level certification for those who just have classroom knowledge and then a higher level for those that have proven industry experience developing WordPress sites. This is how Project Management Institute structures their certifications with CAPM for beginners and PMP and other specialized certifications for experienced project managers.