Always keep an eye on Brent Hubbs. He's the best in the biz in Knoxville, IMO. He's very conservative and very hesitant to give false hope on anything. He's also respectful and doesn't leak things earlier than they're meant to be leaked.
I'm not saying he knows the conclusion to this situation, but his tone has changed somewhat over the past week or two. In their Q&A tonight, he (& the other mods) seemed more positive on the Gruden front than in the past. Hubbs is a smart guy. Tonight, he didn't shoot down Grumors or try to reign people in. His response was about how he's not sure Gruden wants to coach college football. That way, he gives himself deniability if it doesn't happen. And if/when it does happen, he can say his question all along was not about UT or that desire, but just about whether or not JG wanted to go this route.
He doesn't outright say anything earth shattering, but if you know and follow Hubbs through the years, it's par for the course for him when something big like this is in the works.