if you're looking for a "profile % completion" type of add-on, I don't believe there is one. Maybe you could post this in the jobs section and someone would be willing to build it!!
When you set up user attributes, you can tick options that they are required when a user registers. That way, a user cannot enter a profile that is not complete.
thinking even deeper than that... maybe we could build this with Magic Data ?! Based on specific attributes, the number thereof and % of them not null...
We need a bit more information to be able to help you.