Not good. The feds would not make such a move without pretty solid evidence - but he is still innocent until proven guilty. Guess we'll have to watch and see how it goes.
The problem with all of this isn't this case. The issue is once the Feds get into you anything they find or think they have found (regardless if it is pertinent to the case at hand) is fair game.
Texassports.com site says he was relieved of duties. Given the fact that he can't coach from jail, that sounds like the right call.