Team Sealed Events (and BYEs)
GP San Jose (California) was team sealed. This reply is based of that event, and I expect minimal changes prior to Utrecht. Always consult Relevant Documentation <tm>* to be certain. (* Relevant documentation may only exist in theory or may change without notice, but let's pretend that we are victorious over entropy for now.)
Team Designations:
Teams designate members A, B, and C at the start of the event. In San Jose, our scorekeeper was able to adjust the player order designation prior to the beginning of round one if a team decided they needed to adjust their A-B-C ordering, but the order was locked once the first round began. This was done (if I recall correctly) during the sealed build since only one member is needed to communicate while the others work on the build.
Pairing and Draft Seating:
For each round, each team is paired against one other team–1A plays 2A, 1B plays 2B, and 1C plays 2C. For the draft portion, two teams are seated at one table of six chairs with members in alternate chairs–
1A 2A 1B
2C 1C 2B
Byes and GP Trials:
Team events give one- and two-round byes. There are no three-round byes due to the nature of team events. A player who meets a bye criteria automatically confers that bye onto whatever team he or she is a part of. Byes do not stack–if a team has one member with a one-round bye and one with a two-round bye, the team receives only the higher bye (in this case, a two-round bye). Definitely refer to the format document when it is public to find out the PWP thresholds (San Jose's were 750 and 1,500).
GP Trials for team events are still run as individual player events. The winner of a Trial confers two byes onto his or her team. Yes, this means three of the people in a given Trial could be on the same team for the GP giving them a 3/X chance of actually getting maximum byes at that Trial.