Hi Chris,
yes, you are correct. At the moment only the user account that created the blog can add entries to that blog. A common workaround is to create a general user account such as "NewsEditor" or "Blogger" and share the credentials (username and password) between the people that will contribute to the blog.
Version 03.xx.xx probably will not be implemented with role-based permissions, but this is one of the key features of the next generation 04.xx.xx that will be completely rewritten.
Best regards,
Dario Rossa