Mangino isn't leaving... you've got to be foolish to believe some random article with not a single source listed.
I could see tension building though, seeing that we lost a lot of assistants last year and that it could of been Perkins saying no Mangino wanting to give the guys the money to stay in Lawrence.
Mangino has the program heading in the right direction for Kansas, I mean when's the last time Kansas has been bowl eligible 4 years in a row... never, or even 2 years in a row... never, gone to a BCS bowl, never... actually been competitive in big 12 play consistently, never... etc. etc. He's got the chance to be something really special for KU and I really don't see him bolting.
Although if he did leave, I could see the Offensive Coordinator Ed Warriner getting the head spot and in which case, I don't think much would change at KU.