as far as it all stands right now, its just two sides with armies falling into one of the two categories of order or chaos. I.e. GW proclaimed good and evil armies, that should basically iron that out.
As far as teams, I believe it is the same as last year. During sign up write down what armies you would be willing to field and give the points you could do of said army.
For example Bob has both a tyranid army and a space marine army, he can field 3000 of each but would prefer to play nids. This way the store can set teams up to be fair, everyone gets to play.
After teams are set if the sides decide to get strategic that is up to them, but some sense of a heirarchy should be established to help avoid the confusion of assests and special characters should multiples of a given force happen.