I love gists, but I'd find them a whole bunch more useful if I could create private gists that were attached to an organisation. It would turn gists in to an outstanding internal company snippets library and pastebin.<p>I've also seen companies discourage their employees from using private gists for company code because the access control ends up tied to the individual user and not the company, which causes ownership problems when employees leave.
One thing I wish I had with gists is the ability to drag & drop images into (markdown) documents like you can do when writing issues, comments or such on the site proper. There are quite a few people who like using Gist as a simple writing platform (me included), but ironically all the other places to write text on GitHub work better for that due to the ease of image uploading & embedding in them.<p>Now that I think of it, Markdown preview would also be quite nice to have for Gist. That's yet another thing the site proper has over Gist for writing. It seems that there's even the ability to preview .md files in your repo when editing them in the browser (though you can't upload images here either), that would be great to have for Gist too.