Scott's right on all points, here's some elaboration.
Each bracket has it's own URL , and you can optionally leave commenting on. Using this facility, you can, for example have people comment on each other's brackets or create BuddyPress groups.
I'm building out an awesome demo site, now, to be able to show off some of the features in a few days.
To score a bracket, the system creates a "master bracket" on installation where you tell it who has won each game. Then, run scoring from the settings page, and it will tally the points based on the master bracket.
The scoring is available in the meta_data of the bracket post, so if you want some code to display it today I can certainly provide that.
The Pro Data plugin (commercial) is able to:
a) Automatically update the game scores for the master from our main server
b) run the scoring automatically
c) A bunch of other stuff, particularly notifications when things happen (want to send an SMS message to your member whenever a game is over? you'll be able to do that)
.... automatically, via timed jobs (cron).
Now that the core plugin is released, we're busy updating the with more features. The idea is that you can start building your site and getting members, today, and as we get closer to March, we'll release updates that get closer and closer to the perfect system.
Really looking forward to hearing how you plan to use the plugin so we can make it even better.
Thanks for the feedback!