Design stencils would make it easier to use your patterns in design. For example Yahoo! provides a stencil kit which is mapped to the patterns in their library: http://developer.yahoo.com/ypatterns/wireframes

Add a new section to all pattern, which discusses the usability of each pattern. Something more descriptive than "Why?" section you already have. That would give more credibility to your patterns and would help people to decide whether to use or not to use a pattern.

Would be great if Admins could define new fields, remove or rename field labels in existing form.

I believe that faceted navigation approach would make finding patterns easier.

Should be able to search for patterns by keyword.

Adding multiple examples to the same library at once makes it easier to add patterns, so the libraries wil get more great examples as well

You should let people use Sass for their CSS pattern libraries and maybe even have a place for Sass variables.

It would be awesome if we could have project-wide CSS file that would allow us to share our CSS between projects. We often find our selves copying and pasting boilerplate code on each pattern. Let's have a way to share it across a project.

Instead of sending invites to users, company employees could sign up with their company email addresses to access their company workspace.

1) Use phantomJS (or some other fancy stuff) to generate an image from the HTML I use in the case I don't give you a thumbnail image.
2) If I give you an image, make it the thumbnail by default.
3) Let me drag and drop an image.

Most patterns are related to other patterns, it would be nice to use an already uploaded image for another pattern as well.

I'd like to allow visitors add tags to patterns other users have written.

I want to be able to track changes on patterns and libraries as well as the latest comments.

This should be a no-brainer. I want to invite friends & colleagues to use this tool, but I don't see anywhere to do so. This is definitely the type of app where that would make sense. I see where I could invite colleagues to a shared workspace, but I suspect as a product, design and dev team we'd want to try the product out individually first.

It'd be great if you added an option to print your library so you can have it always at hand, comment on it and share it with your team :-)

New patterns submitted by users could appear in the “Upcoming patterns-list” where other users can review them and vote the patterns to be published they like best. If the pattern receives enough votes, it is promoted as “approved” and gets officially published.

I want to be able to say things like this can be a 'a' tag or a 'button' tag without it trying to make a link on my page. Super annoying!