I don't think it will be too much different for a couple of reasons:
1.) Tennessee is a very "traditional" looking uniform. Similar to other teams in our conference like UGA and Bama, IN THAT, there isn't much you can do to the uni to make it look "cool" without destroying it. For example, look at what Nike did to UGA's unis back a few years ago when they played Boise State in the Dome:
They look like the freaking red power ranger. Bama is a good example, because being a Nike school, their unis haven't really undergone much change at ALL and still look like the "Bama" that we know (and hate).
2.) When Nike took over in the NFL, a lot of the changes made to the unis weren't that drastic, all things considered. Seattle and/or Jacksonville have probably undergone the biggest and most obvious change, IMO, and many other teams have altered fonts for names and numbers, made helmet logos bigger, etc., but that's about it that I've noticed.
I just don't think Nike will go all "Oregon-esque" on us like some are hoping (heaven help us if they do). I am however looking forward to the change and what it will bring.