I don't think Arkansas is leaving either and I don't think BYU will join. But why exactly doesn't NIU bring a Chicago market if TCU is supposed to bring a Dallas market? I know that NIU isn't IN Chicago, but it's very close and most of it's students come from Chicago.
I love how this has to be explained every single day...
NIU doesn't give anybody the Chicago market because most people in Chicago couldn't even tell you where DeKalb IS, much less that there's a school named Northern Illinois University located there. Chicago only cares about Notre Dame and the Big 10, particularly Wisconsin, Illinois, and Northwestern (solely because it's located there). That's it. Bumping NIU up to BCS won't cause people to give a **** about either NIU or the Big 12. If the Big 12 truly wants Chicago market penetration they have to do the unthinkable and add ND or raid the Big 10, both of which are extremely unlikely.
See, what people who are just throwing names of schools out there don't get is presence in the market doesn't give you the market - people in the market have to care. It's the major reason why NIU or Memphis or (name your Texas school) to the Big 12 and Rutgers and/or Syracuse to the Big 10 is a bad idea - yeah, they're ideally located to a market that neither conference has acquired yet, however, adding that school in that market doesn't give the conference that market because nobody in that market CARES.
If the Big 12 is adding a Memphis or Houston or NIU, it's because Texas and Oklahoma left and the conference is in survival mode and a severely degraded level of relevance is deemed preferable to becoming extinct.
By the way, TCU doesn't give ANYBODY the Dallas market, especially not the Big 12, especially since it already owns it with Texas and OU. TCU is attractive to the Big East because of it's recent success and "opening" of Texas recruits to the Big East.