My hope is that they just don't use classic trilogy characters and recast them.
That'd ruin it for sure.
Honestly, just make one in the future with a new plot and cast but in the same universe (which is a weird phrase to say when referencing a sci-fi space series). Maybe bring back an old Han Solo or Leia for quick cameos, but I'd rather a fresh take to the series (truthfully, I thought old Spock was a pretty cool plot point in 2009 J.J. Star Trek).
The series has a wonderful concept and lore, I'd rather something newer that expands on that and less on the previous saga.... it's been done.
The problem though is that the old saga isn't done yet. For instance, the New Republic hasn't been established yet. Additionally, despite their losses during the battle of the second Death Star, neither the Empire or the remaining Sith been cleared out yet (and one of their plans is to bring back the Emperor via, not one, but two clones of him). And then there's what the main characters do during all of this, which I'll abstain from posting due to possible spoiler reasons.
But yeah, if the second trilogy had dealt with episodes 7-9 instead of 1-3 it wouldn't have been so bad but at this point the original actors are all too old at this point unless they make it like 30 years into the future and change some of the plotted details around.