#5 - Oct. 25, 2011, 4 a.m.
It's all integrating into the Battle.net site now. =) At the top in the search bar, just punch in the character name and "@" and the realm.
E.g.
Crithto @ Stormwind
(Disclaimer: This example will yield no information as my level of sneakiness is too much for the system to handle.)EDIT: I should clarify a bit ... you'll want to search for a character in said arena team and from there you can see the team. You can also try searching normally for the arena team name.