Here's what makes me cautious about TFA:
1. What worked in the late 70s/early 80s won't necessarily translate well for modern audiences.
2. JJ Abrams's last film was Star Trek Into Darkness; and the rest of his filmography isn't exactly stellar.
3. Harrison Ford hasn't been in a good movie since maybe The Fugitive, and the last time he played an iconic character it was Indiana Jones and The Kingdom Of The Crystal Skull.
4. Remember when we were excited about Episode I, and thought it would bring Star Wars back to its glory days? History might be repeating itself, as the motivations for making TFA are the exact same as Prequels 15 years ago.