I'd ask you to watch Gabe Zichermann's Google Tech Talk - from 8:00 min to 8:40 - to understand my question:
When Gabe says "parents and teachers got involved" - I can't help but hearing "researchers got involved". In other words, my question is: How do we avoid the edutainment trap? Applying game mechanics is one thing - applying them in a way that actually works however, is a hugely complex matter that even professional game designers get wrong more often than not. I believe we need to ask ourselves what sets market research apart and what experience and skills we have, that would justify optimism in terms of fairing any better than the 'teachers and parents'.