I haven't been able to get an answer on this yet, but I want to track User Registrations as Conversions using Google Analytics. 

To do this, I need have the registration step call a JavaScript snippet on success.  Two ways to do it.  One is to allow us to specify script to call, or the other is to allow us to specify a "Registration Complete" page.  This would apply for any third party tracking software I would think.

Does the ability to do this currently exist without modifying core code?