I would love to see a setup so that we would be able to turn an existing website into one where there is a registered user (possibly paid subscriber VIP section?) option. Many sites out there require registration before posting copmments (which is another program I would like to see - a comment section) and being able to have people sign up as registered users would be great.

Hmmm, I think what you are asking for is a database driven site: You want your audience to be able to register (possibly paying), then you want the site to register the user without you having to "do" anything other than monitor and maintain. This requires a database and appropriate coding that will allow your user (your website) to communicate to the database.
There is a work-around. Coffee Cup's Password Wizard 5.0 http://www.coffeecup.com/password-wizard. With this software you can have registered users BUT you are the gatekeeper. That means you must register them and enter them yourself (it requires more work and the users to do not have immediate access to your site-they have to wait for you to add them). This may be acceptable to you (adding users is really easy and the cost is, as far as I have been able to discover, unbeatable).