It would be interesting if the website could auto create tags that are often picked by the users without enough access to create it. For example, if a given tag has X% of tries and no other user has submited it yet.
How would the system recognize it ? when creating a question the system would verify once the user has finished writting on the tag fields or upon the post your question click
Some might think it is a useless thing but i belive it would make it more complete where some times we tend to forget some important tags that might be around ...