The three most encouraging things I've seen so far are the D-line getting their hands up and knocking down some passes, the addition of some power and counter run plays with pulling guards (and I think I even saw a trap once!) Also, the running backs, all 5 deep, have looked good. Bryant, Wilbon, Ozigbo, Rose, and Mazour (sp?) Have all looked good. And not necessarily in that order either.
One thing I'm both very suprised and encouraged by is how close the QB competition is, especially with how well all three have played. Come fall our offense is gonna be good, especially since the o-line doesn't look nearly as bad as some have feared.