You have non-root access to a shell, access to mail and ftp servers, and an apache instance per domain. If you are a good enough programmer there is no reason why you couldn’t write a “panel” for administering your hosting. .
If you are asking about installing your own version of cPanel to administer hosting facilities outside of your user space for reselling or branding the answer is “no”.
Dreamhost has a custom Control Panel for managing various aspects of your account, users, databases, stats, mail, etc. that, in conjunction with the shell is orders of magnitude more flexible and powerful than cPanel; once you become comfortable with it you will never be satisfied with cPanel again.
It is not, however, structured for fully branded reselling.