If you head over to the Armory, you'll notice a new Arena Records feature that includes tools to to track and measure the performance of every Arena team. Here's all the details, straight from Blizzard poster Bornakk:

• "The Match History tab displays every Arena match that a team has played during the season in an interactive graph showing the date, opposing team, and result of each match.
• The Opponent History tab displays a team's Arena matches in relation to the opposing teams faced, which helps track performance against particular team compositions.
• The Match Reports display the same end-of-match results and statistics that appeared in-game."

This seems like a good way for teams to both track their own performance as well as study their fiercest opponents. What do you think? Will you be using this feature?