I manage an organization https://github.com/marklogic. I see we actually have one gist under https://gist.github.com/marklogic/ ; I can't figure out how to get any more gists there though. Is there a way?
I don't think you can currently create gists as an organization account, but in my experience, if your account was a personal account and you created a gist under that account and then upgraded the account to an organization account, the gist stays but no new gists can be created.
Also, seems like this answer on WebApps confirms my experience.
Hope this helps