A problem with my old CC data entry form(not civicrm) made me check the required field status of the name and address info on a CiviEvent registration. I noticed that some fields on the page (such as amount and e-mail) had the red astricsk to indicate that a field was required. But the billing information for the CC did not. It is required, and if you don't fill it in it will complain as it should. But the red asterisk indicator was not there.
I then also checked the CiviContribute page and found the same thing. I am running 1.8 but did confirm this on the CiviCRM Drupal demo site today using the pages listed below.
Its not a big problem, but it would be good to be consistent and not have the user have to get the error msgs to find out which fields are required. Yes I know it won't happen often, but it can happen. Using my old CC sign-up page for an event(implemented before I activated CiviCRM) I just had a user sign up for an event with nothing but their CC# (no name address or email)