Keep in mind, because this is a test, you should expect bugs. The team also notes that UI elements will be incomplete as well. But first, what are Swiss tournaments?
According to the team,
“Swiss is a system in which the number of rounds is based on the number of teams participating. You will not be removed from the tournament after losing in a Swiss round. In each round, each team plays a team with the same record, if possible. All teams will play all the Swiss rounds, unless they get a bye.”
The tournaments will feature Swiss rounds. Once these rounds are done, ArenaNet will take the top teams into a single elimination match. After this, normal proceedings will apply. Some benefits include more chances to play together instead waiting for hours for a tournament.
Note, there are no planned changes to existing rewards for tournaments right now. Automated tournament wins will see increased gold, however.