First of all, thanks for a great plugin.
That said, I have a small suggestion. It would be nice to allow non-admin users (i.e. editors) to access some of the options in the SEO menu, since many times I have content uploaders which are very concerned about SEO. (I know they can edit SEO options per page, but using that menu makes the job way easier.)
I checked the code and found out that I can easily change the capability limitation for the whole plugin, but doing that would show to everyone the Modules option, which should always be restricted to admins only. I guess I could accomplish it by going a little deeper, but I wouldn't like to alter the plugin core code that much.
Are you planning to add role/permissions support eventually?