#1 - April 7, 2008, 10:54 p.m.
Yes, they are practice.
"The first two weeks of the First Qualification Round will be a "practice" period, and during this time Eligible Participants may switch from one team to another without that Arena Team being penalized. After the "Practice Period," all Arena Rating points will be set to 1,500, and Arena Teams shall compete to earn an Arena Rating based on their participation in 3 vs. 3 matches held in the "Arena Player vs. Player Battlegrounds" on the Tournament Servers."
More details on this can be found in the Official Rules (section 7):
http://www.worldofwarcraft.com/pvp/tournament/legal.xml