I am wondering if anyone can offer some guidance for creating role-specific content.  I already know how to change the content of the page for unauthenticated users vs. registered users.  I would like to do something similar for registered users vs. 'premium' users.

What I can't figure out is how to set up the roles so that I can HIDE content from premium users.  For example, let's say I have a page with two text/html modules containing different content.  In the unauthenticated vs. registered users scenario, I can set the permissions to only display the content of one module to one of these two roles.  Thus, if a user is logged in, they see one module and the other is hidden.  If they are not logged in, they see the other module instead.  Easy.

I am probably not being clever enough, but I can't accomplish the same thing in a registered vs. premium users scenario because the premium users are also registered users.  Thus, both modules always display for premium users.  I realize I could force all users into a premium vs. non-premium role, and display content on this basis, but I know of no way to automate dropping the non-premium role when a member subscribes to the premium service.  Has anyone else solved this problem?

As Brian suggested, I think creating a "non-premuim" role is your best bet under DNN 4.x.  Just to be clear:

• Create a "NonPremuim" role and set it to "auto-assign" just like the "Registered Users" role.  Create "Premium" role but do not set "auto-assign".  When you assign a user to "Premium" you'll have to unassign that user from "NonPremium".  You'll thus end up with the following roles:
  
  NonPremuim:  Regular registered users
  Premium:  Special (paid?) users
  Registered Users:  The collection of both Premium and NonPremium users

I've tackled this before and quickly discovered that management of "Premium-versus-nonPremium" content can be a much bigger headache than user role/account management.  To help keep content management ...uh...manageable, I recommend making your "Premium" content easy to identify at a glance:

• SEGREGATE PAGES:  If you can, create "premuim-only" pages for premuim users and alternate "non-premium-only" versions for non-premuim users.  Set each page's VIEW permissions to either "Premium" or "NonPremium" and always uncheck "Registered Users".  Use of segragated pages keeps content tidy and also means you will not need to worry about configuring permissions for individual modules.
   
• IDENTIFY PAGES:  For your "Premium" pages, create a variation of your site skin and change some noticable aspect of the skin (banner, background color, etc) to visually distinguish the "Premium" pages from "NonPremium".  Alternately, use each Premium page's HEADER TAGS settings section to alter the CSS for the page (i.e., override the skin's CSS link to a banner graphic, change the background-color, etc).
   
• IDENTIFY MODULES:  If you MUST support both premium and non-premium users on the same page, give the "Premuim" modules a different-colored container to distinguish them from the non-premium modules.

Besides helping site admins with content management, adding visual cues to "premium" content reminds Premium users why they did whatever they did to get premium access.  Hopefully such reminders encourage those users to renew when their premium period is set to expire.

-mamlin