Here's is a release from the league:
The League’s 17th and 18th teams, Vancouver Whitecaps FC and the Portland Timbers, will each select 10 players during the 10-round draft. Through the Expansion Priority Draft, Portland earned the first selection in the Expansion Draft. Each current MLS club will have the opportunity to protect 11 players from their 2010 roster. Generation adidas players (who will not graduate at the end of the 2010 season) and Home Grown players are automatically protected and do not count against a team’s 11 protected roster spots. Designated Players do not have to be protected unless the player has a no trade clause in his contract. A complete list of the Expansion Draft Rules can be found on the Expansion Draft Page of MLSsoccer.com. Clubs must submit their protected roster to MLS by 2 p.m. on Monday, November 22. The protected rosters will be made public later that afternoon.