There's really only 2 current BCS conferences that would make sense/have any interest in adding TCU: The Big 12 and the SEC. As a Froggie, I don't know that I'd turn down an offer from these 2, but I just don't see it happening. I'd love to get the old Southwest Conference rivalries going again by playing Texas, A&M, Texas Tech, and Baylor every year, but TCU brings nothing to the Big 12... the conference already has recruiting and TV saturation in the Fort Worth area so there really is no plus to adding a team that might just upset the power balance. The SEC would be interesting, but they don't seem to acknowledge the existence of football West of Louisiana and Arkansas. They could get a bit of a bump in Texas recruiting by coming to Fort Worth, but let's face it, that whole conference is so arrogant they already think they can recruit any decent players from Texas.
To be honest, I don't see TCU going anywhere and that's just fine with me. I like the rivalries that we're building with the rest of the MWC and I'm kinda tired of being an NCAA Conference Gypsy (SWC, WAC, CUSA, MWC). Sure the distances for traveling purposes suck, but the destinations are pretty cool... San Diego, Colorado Springs, Laramie... these are all on the list of places I'd like to visit anyway. The Mountains are fabulous, the South... meh.
I'm all for building the MWC into a powerhouse that can't be ignored. Judging from what you guys are doing with that young QB of yours and a increasingly impressive defense, I think if we can add a strong team, split North and South and have a conference championship and regularly whip up on BCS teams, I think we can force our way into the party.
My only fear is that somehow the PAC-10 decide to actually convince Utah & BYU to join and then that's going to probably cause a collapse. I don't think it would happen, but then 20 years ago, I never would have guessed the SWC would disband.