This dude who played AD&D, White Wolf, Forge stuff and blogs about old school D&D is doing a survey:
http://bxblackrazor.blogspot.com/2012/02/rpg-gaming-survey-your-help-needed.html
It’s a bit more complicated than your typical web survey:
Go to the download page [...] and download the GAMING SURVEY. The document is an MS Excel sheet. Read the instructions at the top; then enter the information in the open cells (the “colored boxes”). Except for the answer boxes, the cells on the document are all locked, so you can’t accidentally type over a question or anything. Once you’ve finished, save the document and then email it to the following email address [...]
My hope is that it will replace speculation on who we are and what we play with some facts. The only real quantitative study I’ve seen is old stuff from 1999 done by Wizards of the Coast. The data is not available, only some conclusions. Maybe we can get an update using JB’s effort?