I think "how can you teach this to beginners?" is a fantastic, low-hanging fruit option for encouraging the wizards to think about that very important type of user.

Other than a more broad "how is the language as a whole faring?" test, which might be done through surveys or other product-style research, I think this is just plainly a hard problem to approach, just by the nature that it's largely about user experience.

"How does this fit with everything else beginners have to learn to understand basic code?" is sorely needed.