Well if nothing else, the prequels have given Disney a really good guage for what NOT to do in a SW movie. Obviously they'll never admit it, but I'm sure thats what's in the back of the mind of everyone who's working on these movies.
I love all the Star Wars films, prequels and all, so I am actully hoping that Disney doesn't just decide to ignore what Lucas has accomplished. They need to respect what has already been put on film, whether or not those movies met with approval from every aging fanboy. The prequels have a huge contingent of fans and were very successful, so what I don't want to see are Star Wars films trying to alter what was Lucas's story. It's his universe from top to bottom, Disney needs to still respect that.