Norm, I sent you the wrong link. Here's the correct one for pro team licensing:
http://www.usacycling.org/forms/proxct/09ProMTB-TeamMembership.pdf
Basically, if you want to be tabulated in the series standings for the Pro XC Tour starting this year, you need to be a member of a licensed pro team. Privateers can start their own teams by paying for the team license ($250) in addition to their pro racing license.
This pro team requirement is ONLY for the Pro XCT right now, and any licensed pro racer can still show up and race pro at those races, they just won't be included in the overall series awards unless they're a member of a pro team. This does not affect any non-Pro XCT races, including the national championships.
But anyone who's traveling across the country to race all the Pro XCT races will either be a part of a pro team, or pay the $250 to get their own team license.