Display profile fields for existing (authenticated) users

I'm working on a project where the desired functionality is to have certain "conference information" profile fields display for authenticated users, even if they've already got an account and those fields have been filled in. The benefit is that you have certain fields that folks have to see and confirm (or fill in for the first time) as part of the registration workflow.

Currently, we don't show any user profile fields. This feature would change that, but for authenticated users only, so that we're not exposing profile field information to anyone who knows the email address of users on the site ;).