At least according to Berry Tramel at The Oklahoman - http://blog.newsok.com/berrytramel/2010/10/05/college-football-will-texas-keep-will-muschamp/
Here is an excerpt -
"A Texas source said over the weekend that UT might encourage Mack Brown to retire, that the ‘Horns might be ready to commence with the Muschamp era. Not because of any dissatisfaction of Brown, but because of a belief in Muschamp. That’s the extent of Texas’ devotion to Muschamp, who is in his third year as the UT defensive coordinator and has been designated Brown’s successor."
It would be interesting to know who the "source" is and how much credibility the source has - assuming there's even a shred of truth. I still don't see Georgia letting Richt go this year despite the losing record - I think they've got too much invested and don't want to shell out millions to let him go and millions more to bring someone in. But that's college football politics, so what do I know?
There's rumor LSU would like to throw Miles out too.