I would like all users to be automatically assigned student role and enrolled in every course on the site.
I would like this to apply whenever new users enroll and also when new courses are created.
What would be the best way to achieve this?
Assigning student role system wide would appear to solve the problem but this functionality appears to have been removed in 2.0.
Well yes - the assign system roles was removed from 2.0 -because for the most part you don't normally need to assign roles system wide unless you are admin or possibly a global course creator. Students tend to be students just in the courses they are doing and not all the courses on your Moodle. The system wide role caused a lot of confusion with students being able to access every course on Moodle even when they weren't meant to. However, you presumably have a very valid reason for wanting this - I haven't tried this but I assume you can create a new role and give it all the capabilities of the student role and then set that up as a system role -which would get you back to the Old Way, I think