I love the fact the Users sort shows the people with the highest reputation but I think it would be super helpful to have top users by tags too. That way more people could standout for their efforts here and more people would be incented to contribute.
What I'm thinking is a list of top 10 tags above the users list that when clicked will take to a users screen with reputation ranking by that tag. The top 10 list could also have a link to all tags with links to top reputation users for each tag. That would also help people coming here to find people to hire to know who is best at what.