Things I want to see:

1) The strongest human characters (Krillin, Tien, Yamcha) fighting Frieza's early forms so we can see how strong they are in comparison.
2) Vegeta getting a rematch and (maybe) getting the killing blow in like he did against the Ginyu Force, so he can have revenge for when Frieza killed him on Namek.
3) More Videl. Because Videl is cool.