Nebraska has reportedly accepted an offer to become the next Big 10 school, following Boise State's move to the Mountain West and Colorado's move to the Pac 10. See Omaha.com for details (if you can access it. Right now its servers seem overwhelmed with traffic).
This move does not surprise me in the least and NU was one of the schools I mentioned as being a likely target of the Big 10 in a previous TSE post. It has a rich football tradition and a huge, passionate national fan base. Lots of peope like to talk about the small media markets that are Omaha and Linclon, but the Husker fan base reaches from coast to coast and border to border. They are passionate, knowledgeable, and they travel well.
Do you need any more convincing? Consider this: they have sold out every single home game since the early 1960's and regularly draw more than 70,000 to their spring game. That is passion.
Where does this leave the rest of the Big XII North (Missouri, Iowa State, Kansas State, and Kansas)? Kansas and Missouri are in the best positions out of those four, Kansas because of its storied basketball program and the program's national appeal and Missouri because of it solid play and decently-sized, if not huge and overly passionate, fan base in many sports. In any case, regardless of what KU and MU do, Kansas State and Iowa State (and Baylor) may well be left scrambling for their lives in major college sports.