It would be great to get a little bit of insight into who's using/adding tags (and potentially encourage people to add them) by adding some stats to the profile page.

Stats could be detailed or basic (see mockup image):

• Mockup A, details: tags voted up + tags voted down
• Mockup B, basic: combine tags voted up + voted down numbers

Either would be a step forward.
edit: Edited to take into account Nicolás' comment that we don't store/differentiate new tag vs upvote in the system