AP Photo/Fort Worth Star-Telegram/Ian McVea
Texas Christian Chancellor Victor J. Boschini Jr.,left, wearing a Big 12 cap) laughs with Big 12 Commissioner Chuck Neinas after a press conference in Fort Worth, Texas, announcing TCU's acceptance of an invitation to join the Big 12 Conference Monday, Oct. 10, 2011.

It's official: TCU is joining the Big 12 next season, and the league is waiting on Missouri to decide its future. The Tigers are considering a move to the Southeastern Conference.

Big 12 interim commissioner Chuck Neinas said Tuesday morning that the conference will stay at 10 members in 2012, regardless of what Missouri decides. That means there will be no more changes to Big 12 membership next year, eliminating any chance that BYU could join that conference in 2012.

"TCU is in, and Neinas all but ruled out any further expansion in the Big 12 until Missouri decides where it will be," writes ESPN.com's David Ubben. "There's some debate within the league about whether it wants 10 or 12 members, but that debate can't be settled, Neinas said, until Missouri decides if it's in or out."

Will the Big 12 eventually expand to 12? If so, is BYU still a candidate to join the Big 12?

Writes Brett McMurphy of CBSSports.com, "The decision to expand to 12 would have a big impact on the Big East. Sources have told CBSSports.com that Louisville is the top candidate of the Big 12 if the league adds one member and if it expands by more than one, West Virginia is another strong candidate. Neinas did not discuss any potential expansion candidates on Tuesday’s conference call."

The Oklahoman's Berry Tramel writes that the addition of TCU is looking better every day.

"Look at all the positive vibes in the few days since it became apparent TCU was headed our way. Can't find a Nebraska? Grow your own," Tramel writes. "West Virginia, Brigham Young, Boise State. All have a better football pedigree than TCU. None sit on I-35 or within 20 minutes of the Big 12 headquarters, but add any or all to the conference, and the Big 12's excitement level and television attractiveness soar."

If the Big 12 does go back to 12 teams, will expansion go west or east? Tramel reports that Oklahoma president David Boren prefers that the league goes east (Louisville and West Virginia) rather than west (BYU and Boise State).