my suggestions......
1.) Have WC supply storage space for shared "team" graphics to be posted with team access via FTP
2.) Have team logo below avatar like Monkey-lizard wizop thing and Stardock Support thing.
3.) Require WC Membership to belong to a team.
4.) Set Maximum team size to promote proliferation.
5.) No Religious or Political teams.
My concerns would be how to avoid this becoming one of those elitist issues we've been accused of in the past.
Some other items to ponder......
Register Team Logos
Team Tee-Shirts
Require all members to get matching tattoos