In order to give maximum creative freedom to the filmmakers and also preserve an element of surprise and discovery for the audience, Star Wars Episodes VII-IX will not tell the same story told in the post-Return of the Jedi Expanded Universe.
The news is unlikely to be a surprise, given George Lucas's previous pronouncements on the issue.
"This is lemma 1.1. We start a new chapter so the numbers all go back to one." -- Prof. Seager, C&O 351